A time-zone offset from Greenwich/UTC, such as
A time-zone offset is the amount of time that a time-zone differs from Greenwich/UTC. This is usually a fixed number of hours and minutes.
Different parts of the world have different time-zone offsets.
The rules for how offsets vary by place and time of year are captured in the
For example, Paris is one hour ahead of Greenwich/UTC in winter and two hours
ahead in summer. The
ZoneId instance for Paris will reference two
ZoneOffset instances - a
+01:00 instance for winter,
+02:00 instance for summer.
In 2008, time-zone offsets around the world extended from -12:00 to +14:00. To prevent any problems with that range being extended, yet still provide validation, the range of offsets is restricted to -18:00 to 18:00 inclusive.
This class is designed for use with the ISO calendar system. The fields of hours, minutes and seconds make assumptions that are valid for the standard ISO definitions of those fields. This class may be used with other calendar systems providing the definition of the time fields matches those of the ISO calendar system.
ZoneOffset must be compared using
Implementations may choose to cache certain common offsets, however
applications must not rely on such caching.
This is a value-based
class; use of identity-sensitive operations (including reference equality
==), identity hash code, or synchronization) on instances of
ZoneOffset may have unpredictable results and should be avoided.
equals method should be used for comparisons.
This class is immutable and thread-safe.