This is inspired by both Threeten [1] and Joda-Time [2], which are well-engineered Java libraries for date/time concepts.
I have often wished for that API to be available in other environments, so this is definitely a welcome addition to JS.
Note that the authors of the library are confused -- Threeten-(backport) and Joda-Time are different libraries with different behaviors, and one isn't an "aka." for another. However, Joda-Time's author went on to develop Threeten based on lessons learned, and this library purports to be a JS port of Threeten-Backport.
[1] https://github.com/ThreeTen/threetenbp
[2] http://www.joda.org/joda-time/
