Provides classes and methods to work with dates and durations.

This includes:

- `DateUtils` - a set of static utility methods for working with dates
- `FastDateFormat` - a replacement for `SimpleDateFormat` that is fast and thread-safe
- `DateFormatUtils` - a formatting class for dates
- `StopWatch` - a duration timer

@since 2.0

These classes are immutable (and therefore thread-safe) apart from {@link StopWatch}.