Time Zone Abbreviations

64 abbreviations · part of Units of Measurement Abbreviations

Abbreviations for time standards (UTC, GMT, TAI) and regional time zones, with their offsets from Coordinated Universal Time and their daylight saving rules. Many abbreviations are ambiguous, since CST, IST, BST, AST and PST each name more than one zone, so international schedules are clearest when they add a UTC offset (UTC-5) or an IANA zone name such as America/New_York. In the US and Canada, daylight saving time runs from the second Sunday in March to the first Sunday in November; in the EU and UK, from the last Sunday in March to the last Sunday in October.

AbbreviationStands forDescription
ACDTAustralian Central Daylight TimeSouth Australia and Broken Hill switch to this UTC+10:30 daylight time from the first Sunday in October to the first Sunday in April.
ACSTAustralian Central Standard TimeUTC+9:30, used in South Australia, the Northern Territory and the city of Broken Hill in New South Wales.
ADTAtlantic Daylight TimeSummer time of Canada's Maritime provinces and Bermuda, three hours behind UTC, observed from the second Sunday in March to the first Sunday in November.
AEDTAustralian Eastern Daylight TimeSummer time of New South Wales, Victoria, Tasmania and the ACT, UTC+11, from the first Sunday in October to the first Sunday in April.
AESTAustralian Eastern Standard TimeUTC+10, the standard time of Queensland, New South Wales, Victoria, Tasmania and the Australian Capital Territory.
AKDTAlaska Daylight TimeSummer time in most of Alaska, eight hours behind UTC, from the second Sunday in March to the first Sunday in November.
AKSTAlaska Standard TimeAlaska's winter time, nine hours behind UTC, used in Anchorage, Fairbanks, Juneau and most of the state.
AoEAnywhere on EarthA deadline convention, widely used for academic conference submissions, meaning a deadline is met as long as the stated date has not ended anywhere on the planet.
ARTArgentina TimeArgentina's single time zone, UTC−3, used all year in Buenos Aires and across the country.
ASTArabia Standard TimeThree hours ahead of UTC all year, Arabia Standard Time covers Saudi Arabia, Kuwait, Qatar, Bahrain, Iraq and Yemen, none of which observes daylight saving.
AWSTAustralian Western Standard TimeWestern Australia's time, UTC+8, kept all year.
BRTBrasilia TimeOfficial time of Brazil's capital and its populous southeast, including Sao Paulo and Rio de Janeiro, three hours behind UTC.
BSTBritish Summer TimeThe daylight saving time of the United Kingdom, one hour ahead of GMT (UTC+1), used from the last Sunday in March to the last Sunday in October.
CATCentral Africa TimeTwo hours ahead of UTC year-round, Central Africa Time is used in Zambia, Zimbabwe, Malawi, Mozambique, Botswana, Rwanda, Burundi, Namibia, Sudan, South Sudan and the…
CDTCentral Daylight TimeChicago, Dallas and Winnipeg move to CDT for the warmer months: five hours behind UTC, from the second Sunday in March to the first Sunday in November.
CESTCentral European Summer TimeSummer time of the Central European zone, UTC+2, in force from 01:00 UTC on the last Sunday in March to 01:00 UTC on the last Sunday in October.
CETCentral European TimeWinter time of most of continental Europe, UTC+1, including Germany, France, Italy, Spain, Poland, the Netherlands and Scandinavia, plus Algeria and Tunisia all year.
ChSTChamorro Standard TimeOfficial time of Guam and the Northern Mariana Islands, US territories in the western Pacific, ten hours ahead of UTC.
CSTCentral Standard Time (North America)Winter time of the central United States and Canada, six hours behind UTC, used from the first Sunday in November to the second Sunday in March.
CTCentral TimeGeneric label for the US Central Time Zone, covering CST (UTC−6) and CDT (UTC−5).
DSTDaylight saving timeAdvancing clocks by one hour in warmer months so that evenings have more daylight.
EATEast Africa TimeUsed year-round in Kenya, Tanzania, Uganda, Ethiopia, Somalia, Eritrea, Djibouti and Madagascar, East Africa Time is three hours ahead of UTC.
EDTEastern Daylight TimeDaylight time for the US and Canadian Eastern zone, four hours behind UTC, observed from the second Sunday in March to the first Sunday in November.
EESTEastern European Summer TimeFinland, the Baltic states, Ukraine, Romania, Bulgaria, Greece and Cyprus move three hours ahead of UTC for EEST, from the last Sunday in March to the last Sunday in…
EETEastern European TimeTwo hours ahead of UTC, Eastern European Time is the winter time of Finland, the Baltic states, Ukraine, Romania, Bulgaria, Greece and Cyprus, and the year-round time…
ESTEastern Standard TimeWinter time of the eastern United States and Canada, five hours behind UTC, in effect from the first Sunday in November to the second Sunday in March.
ETEastern TimeGeneric label for the time in the US Eastern Time Zone, covering both Eastern Standard Time (UTC−5) and Eastern Daylight Time (UTC−4).
GMTGreenwich Mean TimeMean solar time at the Royal Observatory in Greenwich, London, and the legal winter time of the UK.
GSTGulf Standard TimeYear-round time of the United Arab Emirates and Oman, four hours ahead of UTC.
HKTHong Kong TimeHong Kong's official time, UTC+8 all year, identical to China Standard Time.
HSTHawaii-Aleutian Standard TimeTen hours behind UTC, HST is the year-round time of Hawaii and the winter time of the western Aleutian Islands.
ICTIndochina TimeShared by Thailand, Vietnam, Cambodia and Laos, Indochina Time is seven hours ahead of UTC all year.
IDLInternational Date LineAn imaginary line roughly following the 180° meridian through the Pacific Ocean, where the calendar date changes by one day.
IRSTIran Standard TimeIran's official time, UTC+3:30, one of the few half-hour offsets in the world.
ISTIndia Standard TimeUTC+5:30, the single time zone for all of India, also used in Sri Lanka.
JSTJapan Standard TimeJapan's single time zone, UTC+9, used year-round from Hokkaido to Okinawa.
KSTKorea Standard TimeSouth Korea's time, UTC+9 all year, the same as Japan.
LMTLocal mean timeMean solar time at a specific longitude, used by towns before standard time zones.
LTLocal timeClock time at a particular place, including its zone offset and any daylight saving.
MDTMountain Daylight TimeSummer time of the Mountain zone, six hours behind UTC, observed from the second Sunday in March to the first Sunday in November in places such as Denver, Salt Lake…
MSKMoscow Standard TimeMoscow time, UTC+3 all year, used in Moscow, St.
MSTMountain Standard TimeSeven hours behind UTC, MST is the winter time of the Rocky Mountain region of the US and Canada and the year-round time of most of Arizona.
MTMountain TimeGeneric label for the US and Canadian Mountain Time Zone, covering MST (UTC−7) and MDT (UTC−6).
NDTNewfoundland Daylight TimeNewfoundland's summer time, UTC−2:30, observed from the second Sunday in March to the first Sunday in November.
NPTNepal TimeOne of the very few time zones with a 45-minute offset, UTC+5:45, used throughout Nepal.
NSTNewfoundland Standard TimeOne of the few half-hour offsets in the Americas, UTC−3:30, used on the island of Newfoundland and in southeastern Labrador.
NZDTNew Zealand Daylight TimeUTC+13, New Zealand's summer time from the last Sunday in September to the first Sunday in April.
NZSTNew Zealand Standard TimeNew Zealand's winter time, UTC+12, used from the first Sunday in April to the last Sunday in September.
PDTPacific Daylight TimeSeven hours behind UTC, PDT is the warm-season clock of the US West Coast and British Columbia, observed from the second Sunday in March to the first Sunday in November.
PKTPakistan Standard TimePakistan's single time zone, UTC+5, used year-round in Karachi, Lahore and Islamabad.
PSTPacific Standard TimeWinter time of the US West Coast, British Columbia and Baja California, eight hours behind UTC, in effect from the first Sunday in November to the second Sunday in March.
PTPacific TimeGeneric label for the US and Canadian Pacific Time Zone, covering PST (UTC−8) and PDT (UTC−7).
SASTSouth African Standard TimeSingle year-round zone of South Africa, Lesotho and Eswatini, two hours ahead of UTC.
SGTSingapore Standard TimeSingapore's official time, UTC+8, used all year.
SSTSamoa Standard TimeTime in American Samoa and Midway Atoll, eleven hours behind UTC, among the last places on Earth to see each day end.
TAIInternational Atomic TimeA continuous time scale computed by the International Bureau of Weights and Measures from about 450 atomic clocks in more than 80 laboratories worldwide.
TRTTurkey TimeTurkey's official time, UTC+3, kept all year since 2016 when the country stayed on summer time permanently.
UT1Universal Time 1Astronomical time based on Earth's actual rotation angle, measured by very-long-baseline radio interferometry of distant quasars.
UTCCoordinated Universal TimeThe primary time standard by which the world regulates clocks, kept within 0.9 second of mean solar time at 0° longitude by occasional leap seconds.
WATWest Africa TimeUsed in Nigeria, Cameroon, Angola, the western Democratic Republic of the Congo, Gabon, Niger and Chad, West Africa Time is one hour ahead of UTC, with no daylight…
WESTWestern European Summer TimePortugal, Madeira, the Canary Islands and the Faroe Islands use WEST, UTC+1, from the last Sunday in March to the last Sunday in October.
WETWestern European TimeWinter time of Portugal (except the Azores), Madeira, the Canary Islands and the Faroe Islands, at UTC+0.
WIBWaktu Indonesia Barat (Western Indonesia Time)Western Indonesia Time, UTC+7, used on Sumatra, Java (including Jakarta) and western and central Kalimantan.
ZZulu time (UTC)Military and aviation designation for UTC, written as a Z after a time, as in 1430Z.

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