ThreeTen provides a modern date and time library for Java and is the reference implementation for JSR-310. It includes many of the lessons of the Joda-Time project and aims to standardise date and time concepts in computing.
- Represent dates, times, date-times and instants
- Represent periods and durations
- Format and parse
This project is an improvement on Joda-Time (a feat in itself) and such a drastic improvement over what is in the standard library that there is no question of its value. I would expect nothing less coming from the same guy that developed Joda-Time, but it is worthy of praise none-the-less.