Time Zone Abbreviations

Time Zone Abbreviations are a convenient and efficient way of writing a time zone. Times zone abbreviations are not unique to a particular geographic location. As an example, the time zone abbreviation "IST" can refer to Irish Summer Time, Israel Standard Time or Indian Summer Time all of which observe different times.

In addition, more than one time zone abbreviation can be used to describe the same time zone. An example is in Australia where ACST is the official abbreviation for Australian Central Standard Time, however, you frequently see CST used to describe that time zone. There are numerous time zone abbreviations which are still in use, which differ from the official abbreviations. An example is in the US state of Hawaii. Hawaii is officially in the Hawaii-Aleutian Time Zone which is abbreviated HAST, however, you frequently see the time zone for Hawaii abbreviated as HST for Hawaii Standard Time. For this reason our list of time zone abbreviations includes both official time zone abbreviations, as well as, historic and frequently used abbreviations.

Time Zone Abbreviations offer many advantages over writing the full name of the Time Zone. They are shorter and can be used more effectively to express a time zone such as 2:00 PM EST. Compare this to writing the full name of the time zone which would be 2:00 PM Eastern Standard Time. In verbal communications the opposite is true. It is often preferable for purposes of clarity to use the full time zone name rather than the time zone code. As an example, you may hear on the radio or television a program time announced as 5:00 Eastern Standard Time rather than 5:00 EST.

Military time zones are used worldwide for both military and civilian purposes. They represent each of the twenty four time zones in use around the world. Learn more about Military Time Zones here.

The time zone code for Coordinated Universal Time is (UTC) and the time zone code for Greenwich Mean Time is (GMT). The (-8h) in PST or Pacific Standard Time refers to that time zone being eight hours behind UTC or GMT and so forth for the other Time Zones.

Time Zone Abbreviations with UTC/GMT Offsets