Hawaii Standard Time (HST) is 10 hours behind Coordinated Universal Time (UTC). This time zone is in use during standard time in: North America.
See full time zone mapWhere and When is HST Observed?
North America
US states using HST in the winter and HDT in the summer
US states using HST all year round
Other Time Zones in UTC -10
Some time zones exist that have the same offset as HST, but can be found under a different name: