|Offset||Time Zone Abbreviation & Name||Example City||Current Time|
|UTC -10||HST||Hawaii Standard Time||Honolulu||Fri, 5:30:30 am|
|UTC -9||AKST||Alaska Standard Time||Anchorage||Fri, 6:30:30 am|
|UTC -8||PST||Pacific Standard Time||Los Angeles||Fri, 7:30:30 am|
|UTC -7||MST||Mountain Standard Time||Salt Lake City||Fri, 8:30:30 am|
|UTC -6||CST||Central Standard Time||Chicago||Fri, 9:30:30 am|
|UTC -5||EST||Eastern Standard Time||New York||Fri, 10:30:30 am|
There are 9 time zones by law in the USA and its dependencies, however, adding the time zones of 2 uninhabited US territories gives 11 time zones in total. The contiguous US has 4 standard time zones. In addition Alaska, Hawaii, and 5 US dependencies all have their own time zones. As neither Hawaii nor the 5 dependencies use Daylight Saving Time (DST), there are only 6 corresponding DST time zones.
|Time Zone Abbreviation & Name||Offset||Current Time|
|PT||Pacific Time||UTC -8:00 / -7:00||Fri, 7:30:30 am|
|MT||Mountain Time||UTC -7:00 / -6:00||Fri, 8:30:30 am|
|CT||Central Time||UTC -6:00 / -5:00||Fri, 9:30:30 am|
|ET||Eastern Time||UTC -5:00 / -4:00||Fri, 10:30:30 am|
The time zones in the contiguous US are often referred to by their generic name, without making a difference between standard time and Daylight Saving Time designations. For example, Eastern Time (ET) refers to Eastern Standard Time (EST) or Eastern Daylight Time (EDT), depending on which is currently in use. In practice, this means that the local time in these time zones changes when DST begins and ends.
Note: Local time in these time zones changes when Daylight Saving Time begins and ends.
|Offset||Time Zone Abbreviation & Name||Commences|
|UTC -8||AKDT||Alaska Daylight Time||Mar 10, 2019|
|UTC -7||PDT||Pacific Daylight Time||Mar 10, 2019|
|UTC -6||MDT||Mountain Daylight Time||Mar 10, 2019|
|UTC -5||CDT||Central Daylight Time||Mar 10, 2019|
|UTC -4||EDT||Eastern Daylight Time||Mar 10, 2019|
The above time zones are used during other parts of the year. They will become active again after the next clock change as Daylight Saving Time begins or ends.
|Offset||Time Zone Abbreviation & Name||Dependency||Type||Current Time|
|UTC -12||AoE||Anywhere on Earth||US Minor Outlying Islands||Territory||Fri, 3:30:30 am|
|UTC -11||SST||Samoa Standard Time||American Samoa||Unincorp. unorg. territory||Fri, 4:30:30 am|
|SST||Samoa Standard Time||US Minor Outlying Islands||Territory||Fri, 4:30:30 am|
|UTC -4||AST||Atlantic Standard Time||Puerto Rico||Unincorp. org. territory||Fri, 11:30:30 am|
|AST||Atlantic Standard Time||US Virgin Islands||Unincorp. org. territory||Fri, 11:30:30 am|
|UTC +10||ChST||Chamorro Standard Time||Guam||Unincorp. org. territory||Sat, 1:30:30 am|
|ChST||Chamorro Standard Time||Northern Mariana Islands||Unincorp. org. territory||Sat, 1:30:30 am|
|UTC +12||WAKT||Wake Time||US Minor Outlying Islands||Territory||Sat, 3:30:30 am|
The US dependencies don't use DST.
The US was divided into 4 standard time zones on November 18, 1883, and jurisdiction for the zones was given to the Interstate Commerce Commission (ICC). Since 1967, the US Department of Transportation (DOT) has been responsible for governing time zones in the country.
Time zones in the USA are defined in the U.S. Code, Title 15, Chapter 6, Subchapter IX - Standard Time. The time zones in the law are defined by their offset from Coordinated Universal Time (UTC).
There are 9 official time zones according to the law. In addition the uninhabited atolls of Baker Island (AoE) and Wake Island (WAKT) add to the time zone count, making 11 the total number of time zones in the US.