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# Utilities for supporting date time functions

Sources for datetime are adapted from Howard Hinnant's date library
(https://github.com/HowardHinnant/date).

Sources are taken from changeset 5bdb7e6f31fac909c090a46dbd9fea27b6e609a4
of the above project.

The following changes are made:
- fix internal inclusion paths (from "date/xxx.h" to simply "xxx.h")
- enclose the `date` namespace inside the `arrow_vendored` namespace
- fix 4 declarations like `CONSTCD11 date::day  operator "" _d(unsigned long long d) NOEXCEPT;`
  to not have offending whitespace for modern clang:
  `CONSTCD11 date::day  operator ""_d(unsigned long long d) NOEXCEPT;` 

## How to update

```console
$ cd cpp/src/arrow/vendored/datetime
$ ./update.sh 3.0.3
```