Efficient routines for manipulation of date-time objects while
accounting for time-zones and daylight saving times. The package
includes utilities for updating of date-time components (year, month,
day etc.), modification of time-zones, rounding of date-times, period
addition and subtraction etc. Parts of the 'CCTZ' source code,
released under the Apache 2.0 License, are included in this package.
See <https://github.com/google/cctz> for more details.