Static access to date/time zone providers built into Noda Time and for global configuration where this is unavoidable.
All properties are thread-safe, and the providers returned by the read-only properties cache their results.
Singleton implementation of IClock which reads the current system time.
It is recommended that for anything other than throwaway code, this is only referenced
in a single place in your code: where you provide a value to inject into the rest of
your application, which should only depend on the interface.
A date and time in a particular calendar system. A LocalDateTime value does not represent an
instant on the time line, because it has no associated time zone: "November 12th 2009 7pm, ISO calendar"
occurred at different instants for different people around the world.
The units within a Period. When a period is created to find the difference between two local values,
the caller may specify which units are required - for example, you can ask for the difference between two dates
in "years and weeks". Units are always applied largest-first in arithmetic.