Time zone directory
Abbreviations such as EST, IST, CET and JST — what they mean, where they are used and what time it is there now.
| Abbr. | Name | Current time | UTC offset | DST | Example cities |
|---|---|---|---|---|---|
| UTC | Coordinated Universal Time | — | +00:00 | No | Reykjavik |
| GMT | Greenwich Mean Time | — | +01:00 | Yes | London, Dublin, Lisbon |
| BST | British Summer Time | — | +01:00 | Yes | London, Manchester, Edinburgh |
| CET | Central European Time | — | +02:00 | Yes | Paris, Berlin, Madrid |
| CEST | Central European Summer Time | — | +02:00 | Yes | Paris, Berlin, Madrid |
| EET | Eastern European Time | — | +03:00 | Yes | Athens, Helsinki, Bucharest |
| EST | Eastern Standard Time | — | -04:00 | Yes | New York, Toronto, Miami |
| EDT | Eastern Daylight Time | — | -04:00 | Yes | New York, Toronto, Washington, D.C. |
| CST | Central Standard Time | — | -05:00 | Yes | Chicago, Houston, Dallas |
| CDT | Central Daylight Time | — | -05:00 | Yes | Chicago, Houston, Dallas |
| MST | Mountain Standard Time | — | -06:00 | Yes | Denver, Phoenix, Calgary |
| MDT | Mountain Daylight Time | — | -06:00 | Yes | Denver, Calgary |
| PST | Pacific Standard Time | — | -07:00 | Yes | Los Angeles, San Francisco, Seattle |
| PDT | Pacific Daylight Time | — | -07:00 | Yes | Los Angeles, San Francisco, Seattle |
| AKST | Alaska Standard Time | — | -08:00 | Yes | Anchorage |
| HST | Hawaii Standard Time | — | -10:00 | No | Honolulu |
| AST | Atlantic Standard Time | — | -03:00 | Yes | Halifax |
| BRT | Brasília Time | — | -03:00 | No | São Paulo, Rio de Janeiro |
| ART | Argentina Time | — | -03:00 | No | Buenos Aires |
| IST | India Standard Time | — | +05:30 | No | New Delhi, Mumbai, Bengaluru |
| PKT | Pakistan Standard Time | — | +05:00 | No | Karachi, Lahore, Islamabad |
| NPT | Nepal Time | — | +05:45 | No | Kathmandu |
| BST (BD) | Bangladesh Standard Time | — | +06:00 | No | Dhaka |
| GST | Gulf Standard Time | — | +04:00 | No | Dubai, Abu Dhabi, Muscat |
| AST (SA) | Arabia Standard Time | — | +03:00 | No | Riyadh, Kuwait City, Doha |
| MSK | Moscow Time | — | +03:00 | No | Moscow, Saint Petersburg |
| TRT | Türkiye Time | — | +03:00 | No | Istanbul, Ankara |
| CST (China) | China Standard Time | — | +08:00 | No | Beijing, Shanghai, Shenzhen |
| HKT | Hong Kong Time | — | +08:00 | No | Hong Kong |
| SGT | Singapore Time | — | +08:00 | No | Singapore |
| JST | Japan Standard Time | — | +09:00 | No | Tokyo, Osaka |
| KST | Korea Standard Time | — | +09:00 | No | Seoul, Busan |
| ICT | Indochina Time | — | +07:00 | No | Bangkok, Hanoi, Ho Chi Minh City |
| AEST | Australian Eastern Standard Time | — | +11:00 | Yes | Sydney, Melbourne, Brisbane |
| AEDT | Australian Eastern Daylight Time | — | +11:00 | Yes | Sydney, Melbourne |
| ACST | Australian Central Standard Time | — | +10:30 | Yes | Adelaide, Darwin |
| AWST | Australian Western Standard Time | — | +08:00 | No | Perth |
| NZST | New Zealand Standard Time | — | +13:00 | Yes | Auckland, Wellington |
| SAST | South Africa Standard Time | — | +02:00 | No | Johannesburg, Cape Town, Pretoria |
| EAT | East Africa Time | — | +03:00 | No | Nairobi, Addis Ababa, Kampala |
| WAT | West Africa Time | — | +01:00 | No | Lagos, Kinshasa, Luanda |
About abbreviations and clock changes
Time zone abbreviations are not standardised and not unique. The same two, three or four letters are used by unrelated zones in different parts of the world, sometimes for offsets hours apart, and they change with the season, so the same place reports a different abbreviation in summer than in winter. For anything that has to be unambiguous, quote the UTC offset or the IANA identifier instead; each zone page names the identifier and any clashes its letters are known for.
Daylight saving exists to shift an hour of daylight from the early morning, when most people are asleep, to the evening, when they are not. The dates are set by legislation rather than by astronomy, which is why they differ between countries that are otherwise on the same offset, and why they occasionally change at short notice when a government decides to move or abolish them. Every zone page reads its next changes from the IANA database rather than from a stored rule, so a change a government has announced is reflected as soon as the database carries it.
The city lists on the zone pages cover the larger cities on each offset and are representative rather than exhaustive: a time zone is a legal boundary, not a geographic one, and countries occasionally move between zones or split into more than one.
How it works
The table lists the abbreviations in common use alongside the thing that actually identifies a zone: its IANA identifier. Abbreviations are convenient in prose and unreliable in software. They were never centrally assigned, several are used by unrelated regions, and most change with the season — the same place reports one set of letters in summer and another in winter.
Each row shows the current offset from UTC, whether the zone observes daylight saving, and the larger cities that keep it. The offset is read live from your browser rather than stored, so a row is correct on the day you read it rather than on the day the page was written.
Where a zone does shift, the offset shown is the one in force now. That is the useful answer for scheduling today, but it means a figure copied from this page is not a year-round constant.
Examples
Decoding an abbreviation someone sent you. "The call is at 3pm CST" has at least three readings: Central Standard Time in North America (UTC−6), China Standard Time (UTC+8) and Cuba Standard Time (UTC−5). Fourteen hours separate the extremes. Looking the letters up here shows every candidate, which is usually enough to establish that you need to ask rather than guess.
Finding an identifier a server will accept. If you know a place keeps IST but need something a configuration file understands, the table gives the IANA identifier — Asia/Kolkata rather than three ambiguous letters.
Checking whether an offset moves. The daylight-saving column says whether a zone holds one offset all year or shifts twice, which decides whether a recurring meeting will drift against it.
Practical notes
Treat the abbreviations as labels for humans and the IANA identifiers as the thing to put in software. Abbreviations collide — CST, IST and BST each name at least two unrelated offsets — and they change with the season, so a value copied into a config file will be wrong for half the year.
The offsets shown are current. If you need the offset that will apply on a specific future date, use the converter with that date rather than reading a figure from this table, because a zone that observes daylight saving has two.
Zone membership is a legal question and it does change. Countries have moved between zones, split into two, and abolished daylight saving at a few months' notice. The list reflects the data your browser currently ships; it is not a historical record and it cannot anticipate a change that has not been published.
Frequently asked questions
Why do some abbreviations mean two different things?
Abbreviations grew up regionally and were never centrally allocated. Always pair one with a country or an IANA identifier when it matters.
What is an IANA time zone identifier?
A name such as Europe/Madrid from the time zone database maintained by IANA. It carries the full history of offset and daylight saving rules for that region.
Why do unrelated places share an abbreviation?
Because abbreviations were never standardised. They grew up locally, nobody coordinated them, and the same letters ended up meaning different offsets in different regions. Only the IANA identifier is guaranteed unique.
Which abbreviation applies right now?
The table shows the one in force today, and it changes with the season — the same zone reports BST through the summer and GMT through the winter.
What is an IANA identifier?
The unique name for a zone in the time zone database, written as Region/City — Asia/Kolkata, Europe/London. Unlike an abbreviation it identifies exactly one set of rules.
Why does my zone show a city I do not live in?
Identifiers are named after a representative city, not every place that uses the zone. Europe/London covers all of the UK.
How often does the database change?
Several times a year, whenever a government alters its rules. Your browser picks the changes up when it updates.
Can I search by city?
Yes, the filter matches city names as well as abbreviations and identifiers.