The above time zones are used during other parts of the year. Time Zones Not Currently Being Observed in United States Offset Note: Local time in these time zones changes when Daylight Saving Time begins and ends. In practice, this means that the local time in these time zones changes when DST begins and ends. For example, Eastern Time (ET) refers to Eastern Standard Time (EST) or Eastern Daylight Time (EDT), depending on which is currently in use. 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. Generalized Time Zones in United States Time Zone Abbreviation & Name Since Howland Island and Baker Island constitute the world's westernmost landmasses in relation to the International Date Line, making them the last places on Earth where any date exists, they are sometimes assigned a theoretical 12th time zone called Anywhere on Earth (AoE). As neither Hawaii nor the 5 dependencies use Daylight Saving Time (DST), there are only 6 corresponding DST time zones. In addition, Alaska, Hawaii, and 5 US dependencies all have their own time zones. The contiguous US has 4 standard time zones.

However, adding the time zones of 2 uninhabited US territories, Howland Island and Baker Island, brings the total count to 11 time zones.

There are 9 time zones by law in the USA and its dependencies. Time Zones Currently Being Used in United States Offset Business Date to Date (exclude holidays).

Different time zones in usa