aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/icu/include/unicode/smpdtfmt.h
blob: 4343bfbca53aa95f2965c2450fbfc3f7ad26804d (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
* Copyright (C) 1997-2016, International Business Machines Corporation and
* others. All Rights Reserved.
*******************************************************************************
*
* File SMPDTFMT.H
*
* Modification History:
*
*   Date        Name        Description
*   02/19/97    aliu        Converted from java.
*   07/09/97    helena      Make ParsePosition into a class.
*   07/21/98    stephen     Added GMT_PLUS, GMT_MINUS
*                            Changed setTwoDigitStartDate to set2DigitYearStart
*                            Changed getTwoDigitStartDate to get2DigitYearStart
*                            Removed subParseLong
*                            Removed getZoneIndex (added in DateFormatSymbols)
*   06/14/99    stephen     Removed fgTimeZoneDataSuffix
*   10/14/99    aliu        Updated class doc to describe 2-digit year parsing
*                           {j28 4182066}.
*******************************************************************************
*/

#ifndef SMPDTFMT_H
#define SMPDTFMT_H

#include "unicode/utypes.h"

#if U_SHOW_CPLUSPLUS_API

/**
 * \file
 * \brief C++ API: Format and parse dates in a language-independent manner.
 */

#if !UCONFIG_NO_FORMATTING

#include "unicode/datefmt.h"
#include "unicode/udisplaycontext.h"
#include "unicode/tzfmt.h"  /* for UTimeZoneFormatTimeType */
#include "unicode/brkiter.h"

U_NAMESPACE_BEGIN

class DateFormatSymbols;
class DateFormat;
class MessageFormat;
class FieldPositionHandler;
class TimeZoneFormat;
class SharedNumberFormat;
class SimpleDateFormatMutableNFs;
class DateIntervalFormat;

namespace number {
class LocalizedNumberFormatter;
class SimpleNumberFormatter;
}

/**
 *
 * SimpleDateFormat is a concrete class for formatting and parsing dates in a
 * language-independent manner. It allows for formatting (millis -> text),
 * parsing (text -> millis), and normalization. Formats/Parses a date or time,
 * which is the standard milliseconds since 24:00 GMT, Jan 1, 1970.
 * <P>
 * Clients are encouraged to create a date-time formatter using DateFormat::getInstance(),
 * getDateInstance(), getDateInstance(), or getDateTimeInstance() rather than
 * explicitly constructing an instance of SimpleDateFormat.  This way, the client
 * is guaranteed to get an appropriate formatting pattern for whatever locale the
 * program is running in.  However, if the client needs something more unusual than
 * the default patterns in the locales, he can construct a SimpleDateFormat directly
 * and give it an appropriate pattern (or use one of the factory methods on DateFormat
 * and modify the pattern after the fact with toPattern() and applyPattern().
 *
 * <p><strong>Date and Time Patterns:</strong></p>
 *
 * <p>Date and time formats are specified by <em>date and time pattern</em> strings.
 * Within date and time pattern strings, all unquoted ASCII letters [A-Za-z] are reserved
 * as pattern letters representing calendar fields. <code>SimpleDateFormat</code> supports
 * the date and time formatting algorithm and pattern letters defined by
 * <a href="http://www.unicode.org/reports/tr35/tr35-dates.html#Date_Field_Symbol_Table">UTS#35
 * Unicode Locale Data Markup Language (LDML)</a> and further documented for ICU in the
 * <a href="https://unicode-org.github.io/icu/userguide/format_parse/datetime/#date-field-symbol-table">ICU
 * User Guide</a>. The following pattern letters are currently available (note that the actual
 * values depend on CLDR and may change from the examples shown here):</p>
 *
 * <table border="1">
 *     <tr>
 *         <th>Field</th>
 *         <th style="text-align: center">Sym.</th>
 *         <th style="text-align: center">No.</th>
 *         <th>Example</th>
 *         <th>Description</th>
 *     </tr>
 *     <tr>
 *         <th rowspan="3">era</th>
 *         <td style="text-align: center" rowspan="3">G</td>
 *         <td style="text-align: center">1..3</td>
 *         <td>AD</td>
 *         <td rowspan="3">Era - Replaced with the Era string for the current date. One to three letters for the
 *         abbreviated form, four letters for the long (wide) form, five for the narrow form.</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">4</td>
 *         <td>Anno Domini</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">5</td>
 *         <td>A</td>
 *     </tr>
 *     <tr>
 *         <th rowspan="6">year</th>
 *         <td style="text-align: center">y</td>
 *         <td style="text-align: center">1..n</td>
 *         <td>1996</td>
 *         <td>Year. Normally the length specifies the padding, but for two letters it also specifies the maximum
 *         length. Example:<div align="center">
 *             <center>
 *             <table border="1" cellpadding="2" cellspacing="0">
 *                 <tr>
 *                     <th>Year</th>
 *                     <th style="text-align: right">y</th>
 *                     <th style="text-align: right">yy</th>
 *                     <th style="text-align: right">yyy</th>
 *                     <th style="text-align: right">yyyy</th>
 *                     <th style="text-align: right">yyyyy</th>
 *                 </tr>
 *                 <tr>
 *                     <td>AD 1</td>
 *                     <td style="text-align: right">1</td>
 *                     <td style="text-align: right">01</td>
 *                     <td style="text-align: right">001</td>
 *                     <td style="text-align: right">0001</td>
 *                     <td style="text-align: right">00001</td>
 *                 </tr>
 *                 <tr>
 *                     <td>AD 12</td>
 *                     <td style="text-align: right">12</td>
 *                     <td style="text-align: right">12</td>
 *                     <td style="text-align: right">012</td>
 *                     <td style="text-align: right">0012</td>
 *                     <td style="text-align: right">00012</td>
 *                 </tr>
 *                 <tr>
 *                     <td>AD 123</td>
 *                     <td style="text-align: right">123</td>
 *                     <td style="text-align: right">23</td>
 *                     <td style="text-align: right">123</td>
 *                     <td style="text-align: right">0123</td>
 *                     <td style="text-align: right">00123</td>
 *                 </tr>
 *                 <tr>
 *                     <td>AD 1234</td>
 *                     <td style="text-align: right">1234</td>
 *                     <td style="text-align: right">34</td>
 *                     <td style="text-align: right">1234</td>
 *                     <td style="text-align: right">1234</td>
 *                     <td style="text-align: right">01234</td>
 *                 </tr>
 *                 <tr>
 *                     <td>AD 12345</td>
 *                     <td style="text-align: right">12345</td>
 *                     <td style="text-align: right">45</td>
 *                     <td style="text-align: right">12345</td>
 *                     <td style="text-align: right">12345</td>
 *                     <td style="text-align: right">12345</td>
 *                 </tr>
 *             </table>
 *             </center></div>
 *         </td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">Y</td>
 *         <td style="text-align: center">1..n</td>
 *         <td>1997</td>
 *         <td>Year (in "Week of Year" based calendars). Normally the length specifies the padding,
 *         but for two letters it also specifies the maximum length. This year designation is used in ISO
 *         year-week calendar as defined by ISO 8601, but can be used in non-Gregorian based calendar systems
 *         where week date processing is desired. May not always be the same value as calendar year.</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">u</td>
 *         <td style="text-align: center">1..n</td>
 *         <td>4601</td>
 *         <td>Extended year. This is a single number designating the year of this calendar system, encompassing
 *         all supra-year fields. For example, for the Julian calendar system, year numbers are positive, with an
 *         era of BCE or CE. An extended year value for the Julian calendar system assigns positive values to CE
 *         years and negative values to BCE years, with 1 BCE being year 0.</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center" rowspan="3">U</td>
 *         <td style="text-align: center">1..3</td>
 *         <td>&#30002;&#23376;</td>
 *         <td rowspan="3">Cyclic year name. Calendars such as the Chinese lunar calendar (and related calendars)
 *         and the Hindu calendars use 60-year cycles of year names. Use one through three letters for the abbreviated
 *         name, four for the full (wide) name, or five for the narrow name (currently the data only provides abbreviated names,
 *         which will be used for all requested name widths). If the calendar does not provide cyclic year name data,
 *         or if the year value to be formatted is out of the range of years for which cyclic name data is provided,
 *         then numeric formatting is used (behaves like 'y').</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">4</td>
 *         <td>(currently also &#30002;&#23376;)</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">5</td>
 *         <td>(currently also &#30002;&#23376;)</td>
 *     </tr>
 *     <tr>
 *         <th rowspan="6">quarter</th>
 *         <td rowspan="3" style="text-align: center">Q</td>
 *         <td style="text-align: center">1..2</td>
 *         <td>02</td>
 *         <td rowspan="3">Quarter - Use one or two for the numerical quarter, three for the abbreviation, or four for the
 *         full (wide) name (five for the narrow name is not yet supported).</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">3</td>
 *         <td>Q2</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">4</td>
 *         <td>2nd quarter</td>
 *     </tr>
 *     <tr>
 *         <td rowspan="3" style="text-align: center">q</td>
 *         <td style="text-align: center">1..2</td>
 *         <td>02</td>
 *         <td rowspan="3"><b>Stand-Alone</b> Quarter - Use one or two for the numerical quarter, three for the abbreviation,
 *         or four for the full name (five for the narrow name is not yet supported).</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">3</td>
 *         <td>Q2</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">4</td>
 *         <td>2nd quarter</td>
 *     </tr>
 *     <tr>
 *         <th rowspan="8">month</th>
 *         <td rowspan="4" style="text-align: center">M</td>
 *         <td style="text-align: center">1..2</td>
 *         <td>09</td>
 *         <td rowspan="4">Month - Use one or two for the numerical month, three for the abbreviation, four for
 *         the full (wide) name, or five for the narrow name. With two ("MM"), the month number is zero-padded
 *         if necessary (e.g. "08")</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">3</td>
 *         <td>Sep</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">4</td>
 *         <td>September</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">5</td>
 *         <td>S</td>
 *     </tr>
 *     <tr>
 *         <td rowspan="4" style="text-align: center">L</td>
 *         <td style="text-align: center">1..2</td>
 *         <td>09</td>
 *         <td rowspan="4"><b>Stand-Alone</b> Month - Use one or two for the numerical month, three for the abbreviation,
 *         four for the full (wide) name, or 5 for the narrow name. With two ("LL"), the month number is zero-padded if
 *         necessary (e.g. "08")</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">3</td>
 *         <td>Sep</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">4</td>
 *         <td>September</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">5</td>
 *         <td>S</td>
 *     </tr>
 *     <tr>
 *         <th rowspan="2">week</th>
 *         <td style="text-align: center">w</td>
 *         <td style="text-align: center">1..2</td>
 *         <td>27</td>
 *         <td>Week of Year. Use "w" to show the minimum number of digits, or "ww" to always show two digits
 *         (zero-padding if necessary, e.g. "08").</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">W</td>
 *         <td style="text-align: center">1</td>
 *         <td>3</td>
 *         <td>Week of Month</td>
 *     </tr>
 *     <tr>
 *         <th rowspan="4">day</th>
 *         <td style="text-align: center">d</td>
 *         <td style="text-align: center">1..2</td>
 *         <td>1</td>
 *         <td>Date - Day of the month. Use "d" to show the minimum number of digits, or "dd" to always show
 *         two digits (zero-padding if necessary, e.g. "08").</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">D</td>
 *         <td style="text-align: center">1..3</td>
 *         <td>345</td>
 *         <td>Day of year</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">F</td>
 *         <td style="text-align: center">1</td>
 *         <td>2</td>
 *         <td>Day of Week in Month. The example is for the 2nd Wed in July</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">g</td>
 *         <td style="text-align: center">1..n</td>
 *         <td>2451334</td>
 *         <td>Modified Julian day. This is different from the conventional Julian day number in two regards.
 *         First, it demarcates days at local zone midnight, rather than noon GMT. Second, it is a local number;
 *         that is, it depends on the local time zone. It can be thought of as a single number that encompasses
 *         all the date-related fields.</td>
 *     </tr>
 *     <tr>
 *         <th rowspan="14">week<br>
 *         day</th>
 *         <td rowspan="4" style="text-align: center">E</td>
 *         <td style="text-align: center">1..3</td>
 *         <td>Tue</td>
 *         <td rowspan="4">Day of week - Use one through three letters for the short day, four for the full (wide) name,
 *         five for the narrow name, or six for the short name.</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">4</td>
 *         <td>Tuesday</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">5</td>
 *         <td>T</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">6</td>
 *         <td>Tu</td>
 *     </tr>
 *     <tr>
 *         <td rowspan="5" style="text-align: center">e</td>
 *         <td style="text-align: center">1..2</td>
 *         <td>2</td>
 *         <td rowspan="5">Local day of week. Same as E except adds a numeric value that will depend on the local
 *         starting day of the week, using one or two letters. For this example, Monday is the first day of the week.</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">3</td>
 *         <td>Tue</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">4</td>
 *         <td>Tuesday</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">5</td>
 *         <td>T</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">6</td>
 *         <td>Tu</td>
 *     </tr>
 *     <tr>
 *         <td rowspan="5" style="text-align: center">c</td>
 *         <td style="text-align: center">1</td>
 *         <td>2</td>
 *         <td rowspan="5"><b>Stand-Alone</b> local day of week - Use one letter for the local numeric value (same
 *         as 'e'), three for the short day, four for the full (wide) name, five for the narrow name, or six for
 *         the short name.</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">3</td>
 *         <td>Tue</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">4</td>
 *         <td>Tuesday</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">5</td>
 *         <td>T</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">6</td>
 *         <td>Tu</td>
 *     </tr>
 *     <tr>
 *         <th>period</th>
 *         <td style="text-align: center">a</td>
 *         <td style="text-align: center">1</td>
 *         <td>AM</td>
 *         <td>AM or PM</td>
 *     </tr>
 *     <tr>
 *         <th rowspan="4">hour</th>
 *         <td style="text-align: center">h</td>
 *         <td style="text-align: center">1..2</td>
 *         <td>11</td>
 *         <td>Hour [1-12]. When used in skeleton data or in a skeleton passed in an API for flexible data pattern
 *         generation, it should match the 12-hour-cycle format preferred by the locale (h or K); it should not match
 *         a 24-hour-cycle format (H or k). Use hh for zero padding.</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">H</td>
 *         <td style="text-align: center">1..2</td>
 *         <td>13</td>
 *         <td>Hour [0-23]. When used in skeleton data or in a skeleton passed in an API for flexible data pattern
 *         generation, it should match the 24-hour-cycle format preferred by the locale (H or k); it should not match a
 *         12-hour-cycle format (h or K). Use HH for zero padding.</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">K</td>
 *         <td style="text-align: center">1..2</td>
 *         <td>0</td>
 *         <td>Hour [0-11]. When used in a skeleton, only matches K or h, see above. Use KK for zero padding.</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">k</td>
 *         <td style="text-align: center">1..2</td>
 *         <td>24</td>
 *         <td>Hour [1-24]. When used in a skeleton, only matches k or H, see above. Use kk for zero padding.</td>
 *     </tr>
 *     <tr>
 *         <th>minute</th>
 *         <td style="text-align: center">m</td>
 *         <td style="text-align: center">1..2</td>
 *         <td>59</td>
 *         <td>Minute. Use "m" to show the minimum number of digits, or "mm" to always show two digits
 *         (zero-padding if necessary, e.g. "08").</td>
 *     </tr>
 *     <tr>
 *         <th rowspan="3">second</th>
 *         <td style="text-align: center">s</td>
 *         <td style="text-align: center">1..2</td>
 *         <td>12</td>
 *         <td>Second. Use "s" to show the minimum number of digits, or "ss" to always show two digits
 *         (zero-padding if necessary, e.g. "08").</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">S</td>
 *         <td style="text-align: center">1..n</td>
 *         <td>3450</td>
 *         <td>Fractional Second - truncates (like other time fields) to the count of letters when formatting.
 *         Appends zeros if more than 3 letters specified. Truncates at three significant digits when parsing.
 *         (example shows display using pattern SSSS for seconds value 12.34567)</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">A</td>
 *         <td style="text-align: center">1..n</td>
 *         <td>69540000</td>
 *         <td>Milliseconds in day. This field behaves <i>exactly</i> like a composite of all time-related fields,
 *         not including the zone fields. As such, it also reflects discontinuities of those fields on DST transition
 *         days. On a day of DST onset, it will jump forward. On a day of DST cessation, it will jump backward. This
 *         reflects the fact that is must be combined with the offset field to obtain a unique local time value.</td>
 *     </tr>
 *     <tr>
 *         <th rowspan="23">zone</th>
 *         <td rowspan="2" style="text-align: center">z</td>
 *         <td style="text-align: center">1..3</td>
 *         <td>PDT</td>
 *         <td>The <i>short specific non-location format</i>.
 *         Where that is unavailable, falls back to the <i>short localized GMT format</i> ("O").</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">4</td>
 *         <td>Pacific Daylight Time</td>
 *         <td>The <i>long specific non-location format</i>.
 *         Where that is unavailable, falls back to the <i>long localized GMT format</i> ("OOOO").</td>
 *     </tr>
 *     <tr>
 *         <td rowspan="3" style="text-align: center">Z</td>
 *         <td style="text-align: center">1..3</td>
 *         <td>-0800</td>
 *         <td>The <i>ISO8601 basic format</i> with hours, minutes and optional seconds fields.
 *         The format is equivalent to RFC 822 zone format (when optional seconds field is absent).
 *         This is equivalent to the "xxxx" specifier.</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">4</td>
 *         <td>GMT-8:00</td>
 *         <td>The <i>long localized GMT format</i>.
 *         This is equivalent to the "OOOO" specifier.</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">5</td>
 *         <td>-08:00<br>
 *         -07:52:58</td>
 *         <td>The <i>ISO8601 extended format</i> with hours, minutes and optional seconds fields.
 *         The ISO8601 UTC indicator "Z" is used when local time offset is 0.
 *         This is equivalent to the "XXXXX" specifier.</td>
 *     </tr>
 *     <tr>
 *         <td rowspan="2" style="text-align: center">O</td>
 *         <td style="text-align: center">1</td>
 *         <td>GMT-8</td>
 *         <td>The <i>short localized GMT format</i>.</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">4</td>
 *         <td>GMT-08:00</td>
 *         <td>The <i>long localized GMT format</i>.</td>
 *     </tr>
 *     <tr>
 *         <td rowspan="2" style="text-align: center">v</td>
 *         <td style="text-align: center">1</td>
 *         <td>PT</td>
 *         <td>The <i>short generic non-location format</i>.
 *         Where that is unavailable, falls back to the <i>generic location format</i> ("VVVV"),
 *         then the <i>short localized GMT format</i> as the final fallback.</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">4</td>
 *         <td>Pacific Time</td>
 *         <td>The <i>long generic non-location format</i>.
 *         Where that is unavailable, falls back to <i>generic location format</i> ("VVVV").
 *     </tr>
 *     <tr>
 *         <td rowspan="4" style="text-align: center">V</td>
 *         <td style="text-align: center">1</td>
 *         <td>uslax</td>
 *         <td>The short time zone ID.
 *         Where that is unavailable, the special short time zone ID <i>unk</i> (Unknown Zone) is used.<br>
 *         <i><b>Note</b>: This specifier was originally used for a variant of the short specific non-location format,
 *         but it was deprecated in the later version of the LDML specification. In CLDR 23/ICU 51, the definition of
 *         the specifier was changed to designate a short time zone ID.</i></td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">2</td>
 *         <td>America/Los_Angeles</td>
 *         <td>The long time zone ID.</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">3</td>
 *         <td>Los Angeles</td>
 *         <td>The exemplar city (location) for the time zone.
 *         Where that is unavailable, the localized exemplar city name for the special zone <i>Etc/Unknown</i> is used
 *         as the fallback (for example, "Unknown City"). </td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">4</td>
 *         <td>Los Angeles Time</td>
 *         <td>The <i>generic location format</i>.
 *         Where that is unavailable, falls back to the <i>long localized GMT format</i> ("OOOO";
 *         Note: Fallback is only necessary with a GMT-style Time Zone ID, like Etc/GMT-830.)<br>
 *         This is especially useful when presenting possible timezone choices for user selection,
 *         since the naming is more uniform than the "v" format.</td>
 *     </tr>
 *     <tr>
 *         <td rowspan="5" style="text-align: center">X</td>
 *         <td style="text-align: center">1</td>
 *         <td>-08<br>
 *         +0530<br>
 *         Z</td>
 *         <td>The <i>ISO8601 basic format</i> with hours field and optional minutes field.
 *         The ISO8601 UTC indicator "Z" is used when local time offset is 0.</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">2</td>
 *         <td>-0800<br>
 *         Z</td>
 *         <td>The <i>ISO8601 basic format</i> with hours and minutes fields.
 *         The ISO8601 UTC indicator "Z" is used when local time offset is 0.</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">3</td>
 *         <td>-08:00<br>
 *         Z</td>
 *         <td>The <i>ISO8601 extended format</i> with hours and minutes fields.
 *         The ISO8601 UTC indicator "Z" is used when local time offset is 0.</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">4</td>
 *         <td>-0800<br>
 *         -075258<br>
 *         Z</td>
 *         <td>The <i>ISO8601 basic format</i> with hours, minutes and optional seconds fields.
 *         (Note: The seconds field is not supported by the ISO8601 specification.)
 *         The ISO8601 UTC indicator "Z" is used when local time offset is 0.</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">5</td>
 *         <td>-08:00<br>
 *         -07:52:58<br>
 *         Z</td>
 *         <td>The <i>ISO8601 extended format</i> with hours, minutes and optional seconds fields.
 *         (Note: The seconds field is not supported by the ISO8601 specification.)
 *         The ISO8601 UTC indicator "Z" is used when local time offset is 0.</td>
 *     </tr>
 *     <tr>
 *         <td rowspan="5" style="text-align: center">x</td>
 *         <td style="text-align: center">1</td>
 *         <td>-08<br>
 *         +0530</td>
 *         <td>The <i>ISO8601 basic format</i> with hours field and optional minutes field.</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">2</td>
 *         <td>-0800</td>
 *         <td>The <i>ISO8601 basic format</i> with hours and minutes fields.</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">3</td>
 *         <td>-08:00</td>
 *         <td>The <i>ISO8601 extended format</i> with hours and minutes fields.</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">4</td>
 *         <td>-0800<br>
 *         -075258</td>
 *         <td>The <i>ISO8601 basic format</i> with hours, minutes and optional seconds fields.
 *         (Note: The seconds field is not supported by the ISO8601 specification.)</td>
 *     </tr>
 *     <tr>
 *         <td style="text-align: center">5</td>
 *         <td>-08:00<br>
 *         -07:52:58</td>
 *         <td>The <i>ISO8601 extended format</i> with hours, minutes and optional seconds fields.
 *         (Note: The seconds field is not supported by the ISO8601 specification.)</td>
 *     </tr>
 * </table>
 *
 * <P>
 * Any characters in the pattern that are not in the ranges of ['a'..'z'] and
 * ['A'..'Z'] will be treated as quoted text. For instance, characters
 * like ':', '.', ' ', '#' and '@' will appear in the resulting time text
 * even they are not embraced within single quotes.
 * <P>
 * A pattern containing any invalid pattern letter will result in a failing
 * UErrorCode result during formatting or parsing.
 * <P>
 * Examples using the US locale:
 * <pre>
 * \code
 *    Format Pattern                         Result
 *    --------------                         -------
 *    "yyyy.MM.dd G 'at' HH:mm:ss vvvv" ->>  1996.07.10 AD at 15:08:56 Pacific Time
 *    "EEE, MMM d, ''yy"                ->>  Wed, July 10, '96
 *    "h:mm a"                          ->>  12:08 PM
 *    "hh 'o''clock' a, zzzz"           ->>  12 o'clock PM, Pacific Daylight Time
 *    "K:mm a, vvv"                     ->>  0:00 PM, PT
 *    "yyyyy.MMMMM.dd GGG hh:mm aaa"    ->>  1996.July.10 AD 12:08 PM
 * \endcode
 * </pre>
 * Code Sample:
 * <pre>
 * \code
 *     UErrorCode success = U_ZERO_ERROR;
 *     SimpleTimeZone* pdt = new SimpleTimeZone(-8 * 60 * 60 * 1000, "PST");
 *     pdt->setStartRule( Calendar::APRIL, 1, Calendar::SUNDAY, 2*60*60*1000);
 *     pdt->setEndRule( Calendar::OCTOBER, -1, Calendar::SUNDAY, 2*60*60*1000);
 *
 *     // Format the current time.
 *     SimpleDateFormat* formatter
 *         = new SimpleDateFormat ("yyyy.MM.dd G 'at' hh:mm:ss a zzz", success );
 *     GregorianCalendar cal(success);
 *     UDate currentTime_1 = cal.getTime(success);
 *     FieldPosition fp(FieldPosition::DONT_CARE);
 *     UnicodeString dateString;
 *     formatter->format( currentTime_1, dateString, fp );
 *     cout << "result: " << dateString << endl;
 *
 *     // Parse the previous string back into a Date.
 *     ParsePosition pp(0);
 *     UDate currentTime_2 = formatter->parse(dateString, pp );
 * \endcode
 * </pre>
 * In the above example, the time value "currentTime_2" obtained from parsing
 * will be equal to currentTime_1. However, they may not be equal if the am/pm
 * marker 'a' is left out from the format pattern while the "hour in am/pm"
 * pattern symbol is used. This information loss can happen when formatting the
 * time in PM.
 *
 * <p>
 * When parsing a date string using the abbreviated year pattern ("y" or "yy"),
 * SimpleDateFormat must interpret the abbreviated year
 * relative to some century.  It does this by adjusting dates to be
 * within 80 years before and 20 years after the time the SimpleDateFormat
 * instance is created. For example, using a pattern of "MM/dd/yy" and a
 * SimpleDateFormat instance created on Jan 1, 1997,  the string
 * "01/11/12" would be interpreted as Jan 11, 2012 while the string "05/04/64"
 * would be interpreted as May 4, 1964.
 * During parsing, only strings consisting of exactly two digits, as defined by
 * <code>Unicode::isDigit()</code>, will be parsed into the default century.
 * Any other numeric string, such as a one digit string, a three or more digit
 * string, or a two digit string that isn't all digits (for example, "-1"), is
 * interpreted literally.  So "01/02/3" or "01/02/003" are parsed (for the
 * Gregorian calendar), using the same pattern, as Jan 2, 3 AD.  Likewise (but
 * only in lenient parse mode, the default) "01/02/-3" is parsed as Jan 2, 4 BC.
 *
 * <p>
 * If the year pattern has more than two 'y' characters, the year is
 * interpreted literally, regardless of the number of digits.  So using the
 * pattern "MM/dd/yyyy", "01/11/12" parses to Jan 11, 12 A.D.
 *
 * <p>
 * When numeric fields abut one another directly, with no intervening delimiter
 * characters, they constitute a run of abutting numeric fields.  Such runs are
 * parsed specially.  For example, the format "HHmmss" parses the input text
 * "123456" to 12:34:56, parses the input text "12345" to 1:23:45, and fails to
 * parse "1234".  In other words, the leftmost field of the run is flexible,
 * while the others keep a fixed width.  If the parse fails anywhere in the run,
 * then the leftmost field is shortened by one character, and the entire run is
 * parsed again. This is repeated until either the parse succeeds or the
 * leftmost field is one character in length.  If the parse still fails at that
 * point, the parse of the run fails.
 *
 * <P>
 * For time zones that have no names, SimpleDateFormat uses strings GMT+hours:minutes or
 * GMT-hours:minutes.
 * <P>
 * The calendar defines what is the first day of the week, the first week of the
 * year, whether hours are zero based or not (0 vs 12 or 24), and the timezone.
 * There is one common number format to handle all the numbers; the digit count
 * is handled programmatically according to the pattern.
 *
 * <p><em>User subclasses are not supported.</em> While clients may write
 * subclasses, such code will not necessarily work and will not be
 * guaranteed to work stably from release to release.
 */
class U_I18N_API SimpleDateFormat: public DateFormat {
public:
    /**
     * Construct a SimpleDateFormat using the default pattern for the default
     * locale.
     * <P>
     * [Note:] Not all locales support SimpleDateFormat; for full generality,
     * use the factory methods in the DateFormat class.
     * @param status    Output param set to success/failure code.
     * @stable ICU 2.0
     */
    SimpleDateFormat(UErrorCode& status);

    /**
     * Construct a SimpleDateFormat using the given pattern and the default locale.
     * The locale is used to obtain the symbols used in formatting (e.g., the
     * names of the months), but not to provide the pattern.
     * <P>
     * [Note:] Not all locales support SimpleDateFormat; for full generality,
     * use the factory methods in the DateFormat class.
     * @param pattern    the pattern for the format.
     * @param status     Output param set to success/failure code.
     * @stable ICU 2.0
     */
    SimpleDateFormat(const UnicodeString& pattern,
                     UErrorCode& status);

    /**
     * Construct a SimpleDateFormat using the given pattern, numbering system override, and the default locale.
     * The locale is used to obtain the symbols used in formatting (e.g., the
     * names of the months), but not to provide the pattern.
     * <P>
     * A numbering system override is a string containing either the name of a known numbering system,
     * or a set of field and numbering system pairs that specify which fields are to be formatted with
     * the alternate numbering system.  For example, to specify that all numeric fields in the specified
     * date or time pattern are to be rendered using Thai digits, simply specify the numbering system override
     * as "thai".  To specify that just the year portion of the date be formatted using Hebrew numbering,
     * use the override string "y=hebrew".  Numbering system overrides can be combined using a semi-colon
     * character in the override string, such as "d=decimal;M=arabic;y=hebrew", etc.
     *
     * <P>
     * [Note:] Not all locales support SimpleDateFormat; for full generality,
     * use the factory methods in the DateFormat class.
     * @param pattern    the pattern for the format.
     * @param override   the override string.
     * @param status     Output param set to success/failure code.
     * @stable ICU 4.2
     */
    SimpleDateFormat(const UnicodeString& pattern,
                     const UnicodeString& override,
                     UErrorCode& status);

    /**
     * Construct a SimpleDateFormat using the given pattern and locale.
     * The locale is used to obtain the symbols used in formatting (e.g., the
     * names of the months), but not to provide the pattern.
     * <P>
     * [Note:] Not all locales support SimpleDateFormat; for full generality,
     * use the factory methods in the DateFormat class.
     * @param pattern    the pattern for the format.
     * @param locale     the given locale.
     * @param status     Output param set to success/failure code.
     * @stable ICU 2.0
     */
    SimpleDateFormat(const UnicodeString& pattern,
                     const Locale& locale,
                     UErrorCode& status);

    /**
     * Construct a SimpleDateFormat using the given pattern, numbering system override, and locale.
     * The locale is used to obtain the symbols used in formatting (e.g., the
     * names of the months), but not to provide the pattern.
     * <P>
     * A numbering system override is a string containing either the name of a known numbering system,
     * or a set of field and numbering system pairs that specify which fields are to be formatted with
     * the alternate numbering system.  For example, to specify that all numeric fields in the specified
     * date or time pattern are to be rendered using Thai digits, simply specify the numbering system override
     * as "thai".  To specify that just the year portion of the date be formatted using Hebrew numbering,
     * use the override string "y=hebrew".  Numbering system overrides can be combined using a semi-colon
     * character in the override string, such as "d=decimal;M=arabic;y=hebrew", etc.
     * <P>
     * [Note:] Not all locales support SimpleDateFormat; for full generality,
     * use the factory methods in the DateFormat class.
     * @param pattern    the pattern for the format.
     * @param override   the numbering system override.
     * @param locale     the given locale.
     * @param status     Output param set to success/failure code.
     * @stable ICU 4.2
     */
    SimpleDateFormat(const UnicodeString& pattern,
                     const UnicodeString& override,
                     const Locale& locale,
                     UErrorCode& status);

    /**
     * Construct a SimpleDateFormat using the given pattern and locale-specific
     * symbol data.  The formatter takes ownership of the DateFormatSymbols object;
     * the caller is no longer responsible for deleting it.
     * @param pattern           the given pattern for the format.
     * @param formatDataToAdopt the symbols to be adopted.
     * @param status            Output param set to success/faulure code.
     * @stable ICU 2.0
     */
    SimpleDateFormat(const UnicodeString& pattern,
                     DateFormatSymbols* formatDataToAdopt,
                     UErrorCode& status);

    /**
     * Construct a SimpleDateFormat using the given pattern and locale-specific
     * symbol data.  The DateFormatSymbols object is NOT adopted; the caller
     * remains responsible for deleting it.
     * @param pattern           the given pattern for the format.
     * @param formatData        the formatting symbols to be use.
     * @param status            Output param set to success/faulure code.
     * @stable ICU 2.0
     */
    SimpleDateFormat(const UnicodeString& pattern,
                     const DateFormatSymbols& formatData,
                     UErrorCode& status);

    /**
     * Copy constructor.
     * @stable ICU 2.0
     */
    SimpleDateFormat(const SimpleDateFormat&);

    /**
     * Assignment operator.
     * @stable ICU 2.0
     */
    SimpleDateFormat& operator=(const SimpleDateFormat&);

    /**
     * Destructor.
     * @stable ICU 2.0
     */
    virtual ~SimpleDateFormat();

    /**
     * Clone this Format object polymorphically. The caller owns the result and
     * should delete it when done.
     * @return    A copy of the object.
     * @stable ICU 2.0
     */
    virtual SimpleDateFormat* clone() const override;

    /**
     * Return true if the given Format objects are semantically equal. Objects
     * of different subclasses are considered unequal.
     * @param other    the object to be compared with.
     * @return         true if the given Format objects are semantically equal.
     * @stable ICU 2.0
     */
    virtual bool operator==(const Format& other) const override;


    using DateFormat::format;

    /**
     * Format a date or time, which is the standard millis since 24:00 GMT, Jan
     * 1, 1970. Overrides DateFormat pure virtual method.
     * <P>
     * Example: using the US locale: "yyyy.MM.dd e 'at' HH:mm:ss zzz" ->>
     * 1996.07.10 AD at 15:08:56 PDT
     *
     * @param cal       Calendar set to the date and time to be formatted
     *                  into a date/time string.
     * @param appendTo  Output parameter to receive result.
     *                  Result is appended to existing contents.
     * @param pos       The formatting position. On input: an alignment field,
     *                  if desired. On output: the offsets of the alignment field.
     * @return          Reference to 'appendTo' parameter.
     * @stable ICU 2.1
     */
    virtual UnicodeString& format(  Calendar& cal,
                                    UnicodeString& appendTo,
                                    FieldPosition& pos) const override;

    /**
     * Format a date or time, which is the standard millis since 24:00 GMT, Jan
     * 1, 1970. Overrides DateFormat pure virtual method.
     * <P>
     * Example: using the US locale: "yyyy.MM.dd e 'at' HH:mm:ss zzz" ->>
     * 1996.07.10 AD at 15:08:56 PDT
     *
     * @param cal       Calendar set to the date and time to be formatted
     *                  into a date/time string.
     * @param appendTo  Output parameter to receive result.
     *                  Result is appended to existing contents.
     * @param posIter   On return, can be used to iterate over positions
     *                  of fields generated by this format call.  Field values
     *                  are defined in UDateFormatField.
     * @param status    Input/output param set to success/failure code.
     * @return          Reference to 'appendTo' parameter.
     * @stable ICU 4.4
     */
    virtual UnicodeString& format(  Calendar& cal,
                                    UnicodeString& appendTo,
                                    FieldPositionIterator* posIter,
                                    UErrorCode& status) const override;

    using DateFormat::parse;

    /**
     * Parse a date/time string beginning at the given parse position. For
     * example, a time text "07/10/96 4:5 PM, PDT" will be parsed into a Date
     * that is equivalent to Date(837039928046).
     * <P>
     * By default, parsing is lenient: If the input is not in the form used by
     * this object's format method but can still be parsed as a date, then the
     * parse succeeds. Clients may insist on strict adherence to the format by
     * calling setLenient(false).
     * @see DateFormat::setLenient(boolean)
     *
     * @param text  The date/time string to be parsed
     * @param cal   A Calendar set on input to the date and time to be used for
     *              missing values in the date/time string being parsed, and set
     *              on output to the parsed date/time. When the calendar type is
     *              different from the internal calendar held by this SimpleDateFormat
     *              instance, the internal calendar will be cloned to a work
     *              calendar set to the same milliseconds and time zone as the
     *              cal parameter, field values will be parsed based on the work
     *              calendar, then the result (milliseconds and time zone) will
     *              be set in this calendar.
     * @param pos   On input, the position at which to start parsing; on
     *              output, the position at which parsing terminated, or the
     *              start position if the parse failed.
     * @stable ICU 2.1
     */
    virtual void parse( const UnicodeString& text,
                        Calendar& cal,
                        ParsePosition& pos) const override;


    /**
     * Set the start UDate used to interpret two-digit year strings.
     * When dates are parsed having 2-digit year strings, they are placed within
     * a assumed range of 100 years starting on the two digit start date.  For
     * example, the string "24-Jan-17" may be in the year 1817, 1917, 2017, or
     * some other year.  SimpleDateFormat chooses a year so that the resultant
     * date is on or after the two digit start date and within 100 years of the
     * two digit start date.
     * <P>
     * By default, the two digit start date is set to 80 years before the current
     * time at which a SimpleDateFormat object is created.
     * @param d      start UDate used to interpret two-digit year strings.
     * @param status Filled in with U_ZERO_ERROR if the parse was successful, and with
     *               an error value if there was a parse error.
     * @stable ICU 2.0
     */
    virtual void set2DigitYearStart(UDate d, UErrorCode& status);

    /**
     * Get the start UDate used to interpret two-digit year strings.
     * When dates are parsed having 2-digit year strings, they are placed within
     * a assumed range of 100 years starting on the two digit start date.  For
     * example, the string "24-Jan-17" may be in the year 1817, 1917, 2017, or
     * some other year.  SimpleDateFormat chooses a year so that the resultant
     * date is on or after the two digit start date and within 100 years of the
     * two digit start date.
     * <P>
     * By default, the two digit start date is set to 80 years before the current
     * time at which a SimpleDateFormat object is created.
     * @param status Filled in with U_ZERO_ERROR if the parse was successful, and with
     *               an error value if there was a parse error.
     * @stable ICU 2.0
     */
    UDate get2DigitYearStart(UErrorCode& status) const;

    /**
     * Return a pattern string describing this date format.
     * @param result Output param to receive the pattern.
     * @return       A reference to 'result'.
     * @stable ICU 2.0
     */
    virtual UnicodeString& toPattern(UnicodeString& result) const;

    /**
     * Return a localized pattern string describing this date format.
     * In most cases, this will return the same thing as toPattern(),
     * but a locale can specify characters to use in pattern descriptions
     * in place of the ones described in this class's class documentation.
     * (Presumably, letters that would be more mnemonic in that locale's
     * language.)  This function would produce a pattern using those
     * letters.
     * <p>
     * <b>Note:</b> This implementation depends on DateFormatSymbols::getLocalPatternChars()
     * to get localized format pattern characters. ICU does not include
     * localized pattern character data, therefore, unless user sets localized
     * pattern characters manually, this method returns the same result as
     * toPattern().
     *
     * @param result    Receives the localized pattern.
     * @param status    Output param set to success/failure code on
     *                  exit. If the pattern is invalid, this will be
     *                  set to a failure result.
     * @return          A reference to 'result'.
     * @stable ICU 2.0
     */
    virtual UnicodeString& toLocalizedPattern(UnicodeString& result,
                                              UErrorCode& status) const;

    /**
     * Apply the given unlocalized pattern string to this date format.
     * (i.e., after this call, this formatter will format dates according to
     * the new pattern)
     *
     * @param pattern   The pattern to be applied.
     * @stable ICU 2.0
     */
    virtual void applyPattern(const UnicodeString& pattern);

    /**
     * Apply the given localized pattern string to this date format.
     * (see toLocalizedPattern() for more information on localized patterns.)
     *
     * @param pattern   The localized pattern to be applied.
     * @param status    Output param set to success/failure code on
     *                  exit. If the pattern is invalid, this will be
     *                  set to a failure result.
     * @stable ICU 2.0
     */
    virtual void applyLocalizedPattern(const UnicodeString& pattern,
                                       UErrorCode& status);

    /**
     * Gets the date/time formatting symbols (this is an object carrying
     * the various strings and other symbols used in formatting: e.g., month
     * names and abbreviations, time zone names, AM/PM strings, etc.)
     * @return a copy of the date-time formatting data associated
     * with this date-time formatter.
     * @stable ICU 2.0
     */
    virtual const DateFormatSymbols* getDateFormatSymbols(void) const;

    /**
     * Set the date/time formatting symbols.  The caller no longer owns the
     * DateFormatSymbols object and should not delete it after making this call.
     * @param newFormatSymbols the given date-time formatting symbols to copy.
     * @stable ICU 2.0
     */
    virtual void adoptDateFormatSymbols(DateFormatSymbols* newFormatSymbols);

    /**
     * Set the date/time formatting data.
     * @param newFormatSymbols the given date-time formatting symbols to copy.
     * @stable ICU 2.0
     */
    virtual void setDateFormatSymbols(const DateFormatSymbols& newFormatSymbols);

    /**
     * Return the class ID for this class. This is useful only for comparing to
     * a return value from getDynamicClassID(). For example:
     * <pre>
     * .   Base* polymorphic_pointer = createPolymorphicObject();
     * .   if (polymorphic_pointer->getDynamicClassID() ==
     * .       erived::getStaticClassID()) ...
     * </pre>
     * @return          The class ID for all objects of this class.
     * @stable ICU 2.0
     */
    static UClassID U_EXPORT2 getStaticClassID(void);

    /**
     * Returns a unique class ID POLYMORPHICALLY. Pure virtual override. This
     * method is to implement a simple version of RTTI, since not all C++
     * compilers support genuine RTTI. Polymorphic operator==() and clone()
     * methods call this method.
     *
     * @return          The class ID for this object. All objects of a
     *                  given class have the same class ID.  Objects of
     *                  other classes have different class IDs.
     * @stable ICU 2.0
     */
    virtual UClassID getDynamicClassID(void) const override;

    /**
     * Set the calendar to be used by this date format. Initially, the default
     * calendar for the specified or default locale is used.  The caller should
     * not delete the Calendar object after it is adopted by this call.
     * Adopting a new calendar will change to the default symbols.
     *
     * @param calendarToAdopt    Calendar object to be adopted.
     * @stable ICU 2.0
     */
    virtual void adoptCalendar(Calendar* calendarToAdopt) override;

    /* Cannot use #ifndef U_HIDE_INTERNAL_API for the following methods since they are virtual */
    /**
     * Sets the TimeZoneFormat to be used by this date/time formatter.
     * The caller should not delete the TimeZoneFormat object after
     * it is adopted by this call.
     * @param timeZoneFormatToAdopt The TimeZoneFormat object to be adopted.
     * @internal ICU 49 technology preview
     */
    virtual void adoptTimeZoneFormat(TimeZoneFormat* timeZoneFormatToAdopt);

    /**
     * Sets the TimeZoneFormat to be used by this date/time formatter.
     * @param newTimeZoneFormat The TimeZoneFormat object to copy.
     * @internal ICU 49 technology preview
     */
    virtual void setTimeZoneFormat(const TimeZoneFormat& newTimeZoneFormat);

    /**
     * Gets the time zone format object associated with this date/time formatter.
     * @return the time zone format associated with this date/time formatter.
     * @internal ICU 49 technology preview
     */
    virtual const TimeZoneFormat* getTimeZoneFormat(void) const;

    /**
     * Set a particular UDisplayContext value in the formatter, such as
     * UDISPCTX_CAPITALIZATION_FOR_STANDALONE. Note: For getContext, see
     * DateFormat.
     * @param value The UDisplayContext value to set.
     * @param status Input/output status. If at entry this indicates a failure
     *               status, the function will do nothing; otherwise this will be
     *               updated with any new status from the function.
     * @stable ICU 53
     */
    virtual void setContext(UDisplayContext value, UErrorCode& status) override;

    /**
     * Overrides base class method and
     * This method clears per field NumberFormat instances
     * previously set by {@see adoptNumberFormat(const UnicodeString&, NumberFormat*, UErrorCode)}
     * @param formatToAdopt the NumbeferFormat used
     * @stable ICU 54
     */
    void adoptNumberFormat(NumberFormat *formatToAdopt) override;

    /**
     * Allow the user to set the NumberFormat for several fields
     * It can be a single field like: "y"(year) or "M"(month)
     * It can be several field combined together: "yM"(year and month)
     * Note:
     * 1 symbol field is enough for multiple symbol field (so "y" will override "yy", "yyy")
     * If the field is not numeric, then override has no effect (like "MMM" will use abbreviation, not numerical field)
     * Per field NumberFormat can also be cleared in {@see DateFormat::setNumberFormat(const NumberFormat& newNumberFormat)}
     *
     * @param fields  the fields to override(like y)
     * @param formatToAdopt the NumbeferFormat used
     * @param status  Receives a status code, which will be U_ZERO_ERROR
     *                if the operation succeeds.
     * @stable ICU 54
     */
    void adoptNumberFormat(const UnicodeString& fields, NumberFormat *formatToAdopt, UErrorCode &status);

    /**
     * Get the numbering system to be used for a particular field.
     * @param field The UDateFormatField to get
     * @stable ICU 54
     */
    const NumberFormat * getNumberFormatForField(char16_t field) const;

#ifndef U_HIDE_INTERNAL_API
    /**
     * This is for ICU internal use only. Please do not use.
     * Check whether the 'field' is smaller than all the fields covered in
     * pattern, return true if it is. The sequence of calendar field,
     * from large to small is: ERA, YEAR, MONTH, DATE, AM_PM, HOUR, MINUTE,...
     * @param field    the calendar field need to check against
     * @return         true if the 'field' is smaller than all the fields
     *                 covered in pattern. false otherwise.
     * @internal ICU 4.0
     */
    UBool isFieldUnitIgnored(UCalendarDateFields field) const;


    /**
     * This is for ICU internal use only. Please do not use.
     * Check whether the 'field' is smaller than all the fields covered in
     * pattern, return true if it is. The sequence of calendar field,
     * from large to small is: ERA, YEAR, MONTH, DATE, AM_PM, HOUR, MINUTE,...
     * @param pattern  the pattern to check against
     * @param field    the calendar field need to check against
     * @return         true if the 'field' is smaller than all the fields
     *                 covered in pattern. false otherwise.
     * @internal ICU 4.0
     */
    static UBool isFieldUnitIgnored(const UnicodeString& pattern,
                                    UCalendarDateFields field);

    /**
     * This is for ICU internal use only. Please do not use.
     * Get the locale of this simple date formatter.
     * It is used in DateIntervalFormat.
     *
     * @return   locale in this simple date formatter
     * @internal ICU 4.0
     */
    const Locale& getSmpFmtLocale(void) const;
#endif  /* U_HIDE_INTERNAL_API */

private:
    friend class DateFormat;
    friend class DateIntervalFormat;

    void initializeDefaultCentury(void);

    void initializeBooleanAttributes(void);

    SimpleDateFormat() = delete; // default constructor not implemented

    /**
     * Used by the DateFormat factory methods to construct a SimpleDateFormat.
     * @param timeStyle the time style.
     * @param dateStyle the date style.
     * @param locale    the given locale.
     * @param status    Output param set to success/failure code on
     *                  exit.
     */
    SimpleDateFormat(EStyle timeStyle, EStyle dateStyle, const Locale& locale, UErrorCode& status);

    /**
     * Construct a SimpleDateFormat for the given locale.  If no resource data
     * is available, create an object of last resort, using hard-coded strings.
     * This is an internal method, called by DateFormat.  It should never fail.
     * @param locale    the given locale.
     * @param status    Output param set to success/failure code on
     *                  exit.
     */
    SimpleDateFormat(const Locale& locale, UErrorCode& status); // Use default pattern

    /**
     * Hook called by format(... FieldPosition& ...) and format(...FieldPositionIterator&...)
     */
    UnicodeString& _format(Calendar& cal, UnicodeString& appendTo, FieldPositionHandler& handler, UErrorCode& status) const;

    /**
     * Called by format() to format a single field.
     *
     * @param appendTo  Output parameter to receive result.
     *                  Result is appended to existing contents.
     * @param ch        The format character we encountered in the pattern.
     * @param count     Number of characters in the current pattern symbol (e.g.,
     *                  "yyyy" in the pattern would result in a call to this function
     *                  with ch equal to 'y' and count equal to 4)
     * @param capitalizationContext Capitalization context for this date format.
     * @param fieldNum  Zero-based numbering of current field within the overall format.
     * @param handler   Records information about field positions.
     * @param cal       Calendar to use
     * @param status    Receives a status code, which will be U_ZERO_ERROR if the operation
     *                  succeeds.
     */
    void subFormat(UnicodeString &appendTo,
                   char16_t ch,
                   int32_t count,
                   UDisplayContext capitalizationContext,
                   int32_t fieldNum,
                   char16_t fieldToOutput,
                   FieldPositionHandler& handler,
                   Calendar& cal,
                   UErrorCode& status) const; // in case of illegal argument

    /**
     * Used by subFormat() to format a numeric value.
     * Appends to toAppendTo a string representation of "value"
     * having a number of digits between "minDigits" and
     * "maxDigits".  Uses the DateFormat's NumberFormat.
     *
     * @param currentNumberFormat
     * @param appendTo  Output parameter to receive result.
     *                  Formatted number is appended to existing contents.
     * @param value     Value to format.
     * @param minDigits Minimum number of digits the result should have
     * @param maxDigits Maximum number of digits the result should have
     */
    void zeroPaddingNumber(const NumberFormat *currentNumberFormat,
                           UnicodeString &appendTo,
                           int32_t value,
                           int32_t minDigits,
                           int32_t maxDigits) const;

    /**
     * Return true if the given format character, occurring count
     * times, represents a numeric field.
     */
    static UBool isNumeric(char16_t formatChar, int32_t count);

    /**
     * Returns true if the patternOffset is at the start of a numeric field.
     */
    static UBool isAtNumericField(const UnicodeString &pattern, int32_t patternOffset);

    /**
     * Returns true if the patternOffset is right after a non-numeric field.
     */
    static UBool isAfterNonNumericField(const UnicodeString &pattern, int32_t patternOffset);

    /**
     * initializes fCalendar from parameters.  Returns fCalendar as a convenience.
     * @param adoptZone  Zone to be adopted, or nullptr for TimeZone::createDefault().
     * @param locale Locale of the calendar
     * @param status Error code
     * @return the newly constructed fCalendar
     */
    Calendar *initializeCalendar(TimeZone* adoptZone, const Locale& locale, UErrorCode& status);

    /**
     * Called by several of the constructors to load pattern data and formatting symbols
     * out of a resource bundle and initialize the locale based on it.
     * @param timeStyle     The time style, as passed to DateFormat::createDateInstance().
     * @param dateStyle     The date style, as passed to DateFormat::createTimeInstance().
     * @param locale        The locale to load the patterns from.
     * @param status        Filled in with an error code if loading the data from the
     *                      resources fails.
     */
    void construct(EStyle timeStyle, EStyle dateStyle, const Locale& locale, UErrorCode& status);

    /**
     * Called by construct() and the various constructors to set up the SimpleDateFormat's
     * Calendar and NumberFormat objects.
     * @param locale    The locale for which we want a Calendar and a NumberFormat.
     * @param status    Filled in with an error code if creating either subobject fails.
     */
    void initialize(const Locale& locale, UErrorCode& status);

    /**
     * Private code-size reduction function used by subParse.
     * @param text the time text being parsed.
     * @param start where to start parsing.
     * @param field the date field being parsed.
     * @param stringArray the string array to parsed.
     * @param stringArrayCount the size of the array.
     * @param monthPattern pointer to leap month pattern, or nullptr if none.
     * @param cal a Calendar set to the date and time to be formatted
     *            into a date/time string.
     * @return the new start position if matching succeeded; a negative number
     * indicating matching failure, otherwise.
     */
    int32_t matchString(const UnicodeString& text, int32_t start, UCalendarDateFields field,
                        const UnicodeString* stringArray, int32_t stringArrayCount,
                        const UnicodeString* monthPattern, Calendar& cal) const;

    /**
     * Private code-size reduction function used by subParse. Only for UCAL_MONTH
     * @param text the time text being parsed.
     * @param start where to start parsing.
     * @param wideStringArray the wide string array to parsed.
     * @param shortStringArray the short string array to parsed.
     * @param stringArrayCount the size of the string arrays.
     * @param cal a Calendar set to the date and time to be formatted
     *            into a date/time string.
     * @return the new start position if matching succeeded; a negative number
     * indicating matching failure, otherwise.
     */
    int32_t matchAlphaMonthStrings(const UnicodeString& text, int32_t start,
                        const UnicodeString* wideStringArray, const UnicodeString* shortStringArray,
                        int32_t stringArrayCount, Calendar& cal) const;

    /**
     * Private code-size reduction function used by subParse.
     * @param text the time text being parsed.
     * @param start where to start parsing.
     * @param field the date field being parsed.
     * @param stringArray the string array to parsed.
     * @param stringArrayCount the size of the array.
     * @param cal a Calendar set to the date and time to be formatted
     *            into a date/time string.
     * @return the new start position if matching succeeded; a negative number
     * indicating matching failure, otherwise.
     */
    int32_t matchQuarterString(const UnicodeString& text, int32_t start, UCalendarDateFields field,
                               const UnicodeString* stringArray, int32_t stringArrayCount, Calendar& cal) const;

    /**
     * Used by subParse() to match localized day period strings.
     */
    int32_t matchDayPeriodStrings(const UnicodeString& text, int32_t start,
                                  const UnicodeString* stringArray, int32_t stringArrayCount,
                                  int32_t &dayPeriod) const;

    /**
     * Private function used by subParse to match literal pattern text.
     *
     * @param pattern the pattern string
     * @param patternOffset the starting offset into the pattern text. On
     *        output will be set the offset of the first non-literal character in the pattern
     * @param text the text being parsed
     * @param textOffset the starting offset into the text. On output
     *                   will be set to the offset of the character after the match
     * @param whitespaceLenient <code>true</code> if whitespace parse is lenient, <code>false</code> otherwise.
     * @param partialMatchLenient <code>true</code> if partial match parse is lenient, <code>false</code> otherwise.
     * @param oldLeniency <code>true</code> if old leniency control is lenient, <code>false</code> otherwise.
     *
     * @return <code>true</code> if the literal text could be matched, <code>false</code> otherwise.
     */
    static UBool matchLiterals(const UnicodeString &pattern, int32_t &patternOffset,
                               const UnicodeString &text, int32_t &textOffset,
                               UBool whitespaceLenient, UBool partialMatchLenient, UBool oldLeniency);

    /**
     * Private member function that converts the parsed date strings into
     * timeFields. Returns -start (for ParsePosition) if failed.
     * @param text the time text to be parsed.
     * @param start where to start parsing.
     * @param ch the pattern character for the date field text to be parsed.
     * @param count the count of a pattern character.
     * @param obeyCount if true then the count is strictly obeyed.
     * @param allowNegative
     * @param ambiguousYear If true then the two-digit year == the default start year.
     * @param saveHebrewMonth Used to hang onto month until year is known.
     * @param cal a Calendar set to the date and time to be formatted
     *            into a date/time string.
     * @param patLoc
     * @param numericLeapMonthFormatter If non-null, used to parse numeric leap months.
     * @param tzTimeType the type of parsed time zone - standard, daylight or unknown (output).
     *      This parameter can be nullptr if caller does not need the information.
     * @return the new start position if matching succeeded; a negative number
     * indicating matching failure, otherwise.
     */
    int32_t subParse(const UnicodeString& text, int32_t& start, char16_t ch, int32_t count,
                     UBool obeyCount, UBool allowNegative, UBool ambiguousYear[], int32_t& saveHebrewMonth, Calendar& cal,
                     int32_t patLoc, MessageFormat * numericLeapMonthFormatter, UTimeZoneFormatTimeType *tzTimeType,
                     int32_t *dayPeriod=nullptr) const;

    void parseInt(const UnicodeString& text,
                  Formattable& number,
                  ParsePosition& pos,
                  UBool allowNegative,
                  const NumberFormat *fmt) const;

    void parseInt(const UnicodeString& text,
                  Formattable& number,
                  int32_t maxDigits,
                  ParsePosition& pos,
                  UBool allowNegative,
                  const NumberFormat *fmt) const;

    int32_t checkIntSuffix(const UnicodeString& text, int32_t start,
                           int32_t patLoc, UBool isNegative) const;

    /**
     * Counts number of digit code points in the specified text.
     *
     * @param text  input text
     * @param start start index, inclusive
     * @param end   end index, exclusive
     * @return  number of digits found in the text in the specified range.
    */
    int32_t countDigits(const UnicodeString& text, int32_t start, int32_t end) const;

    /**
     * Translate a pattern, mapping each character in the from string to the
     * corresponding character in the to string. Return an error if the original
     * pattern contains an unmapped character, or if a quote is unmatched.
     * Quoted (single quotes only) material is not translated.
     * @param originalPattern   the original pattern.
     * @param translatedPattern Output param to receive the translited pattern.
     * @param from              the characters to be translited from.
     * @param to                the characters to be translited to.
     * @param status            Receives a status code, which will be U_ZERO_ERROR
     *                          if the operation succeeds.
     */
    static void translatePattern(const UnicodeString& originalPattern,
                                UnicodeString& translatedPattern,
                                const UnicodeString& from,
                                const UnicodeString& to,
                                UErrorCode& status);

    /**
     * Sets the starting date of the 100-year window that dates with 2-digit years
     * are considered to fall within.
     * @param startDate the start date
     * @param status    Receives a status code, which will be U_ZERO_ERROR
     *                  if the operation succeeds.
     */
    void         parseAmbiguousDatesAsAfter(UDate startDate, UErrorCode& status);

    /**
     * Return the length matched by the given affix, or -1 if none.
     * Runs of white space in the affix, match runs of white space in
     * the input.
     * @param affix pattern string, taken as a literal
     * @param input input text
     * @param pos offset into input at which to begin matching
     * @return length of input that matches, or -1 if match failure
     */
    int32_t compareSimpleAffix(const UnicodeString& affix,
                   const UnicodeString& input,
                   int32_t pos) const;

    /**
     * Skip over a run of zero or more Pattern_White_Space characters at
     * pos in text.
     */
    int32_t skipPatternWhiteSpace(const UnicodeString& text, int32_t pos) const;

    /**
     * Skip over a run of zero or more isUWhiteSpace() characters at pos
     * in text.
     */
    int32_t skipUWhiteSpace(const UnicodeString& text, int32_t pos) const;

    /**
     * Initialize SimpleNumberFormat instance
     */
    void initSimpleNumberFormatter(UErrorCode &status);

    /**
     * Initialize NumberFormat instances used for numbering system overrides.
     */
    void initNumberFormatters(const Locale &locale,UErrorCode &status);

    /**
     * Parse the given override string and set up structures for number formats
     */
    void processOverrideString(const Locale &locale, const UnicodeString &str, int8_t type, UErrorCode &status);

    /**
     * Used to map pattern characters to Calendar field identifiers.
     */
    static const UCalendarDateFields fgPatternIndexToCalendarField[];

    /**
     * Map index into pattern character string to DateFormat field number
     */
    static const UDateFormatField fgPatternIndexToDateFormatField[];

    /**
     * Lazy TimeZoneFormat instantiation, semantically const
     */
    TimeZoneFormat *tzFormat(UErrorCode &status) const;

    const NumberFormat* getNumberFormatByIndex(UDateFormatField index) const;

    /**
     * Used to map Calendar field to field level.
     * The larger the level, the smaller the field unit.
     * For example, UCAL_ERA level is 0, UCAL_YEAR level is 10,
     * UCAL_MONTH level is 20.
     */
    static const int32_t fgCalendarFieldToLevel[];

    /**
     * Map calendar field letter into calendar field level.
     */
    static int32_t getLevelFromChar(char16_t ch);

    /**
     * Tell if a character can be used to define a field in a format string.
     */
    static UBool isSyntaxChar(char16_t ch);

    /**
     * The formatting pattern for this formatter.
     */
    UnicodeString       fPattern;

    /**
     * The numbering system override for dates.
     */
    UnicodeString       fDateOverride;

    /**
     * The numbering system override for times.
     */
    UnicodeString       fTimeOverride;


    /**
     * The original locale used (for reloading symbols)
     */
    Locale              fLocale;

    /**
     * A pointer to an object containing the strings to use in formatting (e.g.,
     * month and day names, AM and PM strings, time zone names, etc.)
     */
    DateFormatSymbols*  fSymbols = nullptr;   // Owned

    /**
     * The time zone formatter
     */
    TimeZoneFormat* fTimeZoneFormat = nullptr;

    /**
     * If dates have ambiguous years, we map them into the century starting
     * at defaultCenturyStart, which may be any date.  If defaultCenturyStart is
     * set to SYSTEM_DEFAULT_CENTURY, which it is by default, then the system
     * values are used.  The instance values defaultCenturyStart and
     * defaultCenturyStartYear are only used if explicitly set by the user
     * through the API method parseAmbiguousDatesAsAfter().
     */
    UDate                fDefaultCenturyStart;

    UBool                fHasMinute;
    UBool                fHasSecond;
    UBool                fHasHanYearChar; // pattern contains the Han year character \u5E74

    /**
     * Sets fHasMinutes and fHasSeconds.
     */
    void                 parsePattern();

    /**
     * See documentation for defaultCenturyStart.
     */
    /*transient*/ int32_t   fDefaultCenturyStartYear;

    struct NSOverride : public UMemory {
        const SharedNumberFormat *snf;
        int32_t hash;
        NSOverride *next;
        void free();
        NSOverride() : snf(nullptr), hash(0), next(nullptr) {
        }
        ~NSOverride();
    };

    /**
     * The number format in use for each date field. nullptr means fall back
     * to fNumberFormat in DateFormat.
     */
    const SharedNumberFormat    **fSharedNumberFormatters = nullptr;

    /**
     * Number formatter pre-allocated for fast performance
     * 
     * This references the decimal symbols from fNumberFormatter if it is an instance
     * of DecimalFormat (and is otherwise null). This should always be cleaned up before
     * destroying fNumberFormatter.
     */
    const number::SimpleNumberFormatter* fSimpleNumberFormatter = nullptr;

    UBool fHaveDefaultCentury;

    const BreakIterator* fCapitalizationBrkIter = nullptr;
};

inline UDate
SimpleDateFormat::get2DigitYearStart(UErrorCode& /*status*/) const
{
    return fDefaultCenturyStart;
}

U_NAMESPACE_END

#endif /* #if !UCONFIG_NO_FORMATTING */

#endif /* U_SHOW_CPLUSPLUS_API */

#endif // _SMPDTFMT
//eof