World Time Zones
Browse all IANA time zones with current UTC offsets, DST status, and live local times.
| Abbreviation(s) | Display Name | UTC Offset |
|---|---|---|
| HST | Hawaii Standard Time (HST) | -10:00 |
| AKST, AKDT | Alaska Daylight Time (AKDT) | -08:00 |
| PST, PDT | Pacific Daylight Time (PDT) | -07:00 |
| MST | Mountain Standard Time (Arizona) | -07:00 |
| MST, MDT | Mountain Daylight Time (MDT) | -06:00 |
| CST, CDT | Central Daylight Time (CDT) | -05:00 |
| EST, EDT | Eastern Time (Canada) | -05:00 |
| COT | Colombia Time (COT) | -05:00 |
| PET | Peru Time (PET) | -05:00 |
| EST, EDT | Eastern Daylight Time (EDT) | -04:00 |
| CLT, CLST | Chile Standard Time (CLT) | -04:00 |
| BRT, BRST | Brasilia Time (BRT) | -03:00 |
| ART | Argentina Time (ART) | -03:00 |
| UTC | Coordinated Universal Time (UTC) | +00:00 |
| WAT | West Africa Time (WAT) | +01:00 |
| GMT, BST | British Summer Time (BST) | +01:00 |
| CET, CEST | Central European Time (Germany) | +01:00 |
| CAT | Central Africa Time (CAT) | +02:00 |
| CET, CEST | Central European Summer Time (CEST) | +02:00 |
| EET | Eastern European Time (Egypt) | +02:00 |
| SAST | South Africa Standard Time (SAST) | +02:00 |
| MSK | Moscow Standard Time (MSK) | +03:00 |
| TRT | Turkey Time (TRT) | +03:00 |
| EET, EEST | Eastern European Summer Time (EEST) | +03:00 |
| EAT | East Africa Time (EAT) | +03:00 |
| AST | Arabia Standard Time (AST) | +03:00 |
| GST | Gulf Standard Time (GST) | +04:00 |
| PKT | Pakistan Standard Time (PKT) | +05:00 |
| IST | India Standard Time (IST) | +05:30 |
| SLST | Sri Lanka Standard Time (SLST) | +05:30 |
| BDT | Bangladesh Time (BDT) | +06:00 |
| ICT | Indochina Time (ICT) | +07:00 |
| WIB | Western Indonesia Time (WIB) | +07:00 |
| HKT | Hong Kong Time (HKT) | +08:00 |
| SGT | Singapore Standard Time (SGT) | +08:00 |
| MYT | Malaysia Time (MYT) | +08:00 |
| JST | Japan Standard Time (JST) | +09:00 |
| KST | Korea Standard Time (KST) | +09:00 |
| AEST, AEDT | Australian Eastern Daylight Time (AEDT) | +11:00 |
| NZST, NZDT | New Zealand Daylight Time (NZDT) | +13:00 |
Understanding IANA Time Zone Names
IANA time zone names follow a Region/City format - For example, America/New_York, Europe/London, or Asia/Kolkata. The region is a broad geographic area such as a continent or ocean, and the city is a specific populated place chosen to represent the full set of historical time zone rules for that political jurisdiction.
Cities are used instead of countries for a deliberate reason: countries change. Nations merge, split, rename themselves, or adopt new zones - Sometimes overnight. If the IANA database used country names, every such change would break software worldwide. A city like Kolkata has existed continuously under different spellings (it was "Calcutta" in older entries; the database retains the old name as an alias). Using a stable city name means the identifier remains valid regardless of how political boundaries shift. The database currently contains over 590 distinct identifiers, many of which are aliases pointing to the same underlying rule set.
Not all regions use the continent/city pattern. UTC-based identifiers (Etc/UTC, Etc/GMT+5) follow a different convention inherited from POSIX systems. Note that POSIX reverses the sign: Etc/GMT+5 means UTC-5 in standard notation. This is a well-known historical quirk. Clock.now always displays the standard UTC offset notation (UTC-5, UTC+8, etc.) regardless of how the IANA identifier is internally signed.
UTC Offsets Explained
UTC offsets express how far a time zone is ahead of or behind Coordinated Universal Time. A positive offset means the local clock is ahead of UTC (east of the prime meridian); a negative offset means it is behind (west). Not all offsets are whole hours - Some jurisdictions use 30-minute or even 15-minute increments.
| UTC Offset | Example IANA Zone | Region / Notes |
|---|---|---|
| UTC-12:00 | Etc/GMT+12 | Baker Island, Howland Island (uninhabited US territories) |
| UTC-11:00 | Pacific/Pago_Pago | American Samoa, Niue |
| UTC-10:00 | Pacific/Honolulu | Hawaii (no DST), Cook Islands |
| UTC-08:00 | America/Los_Angeles | US Pacific Time (PST/PDT with DST) |
| UTC-07:00 | America/Denver | US Mountain Time; Arizona stays UTC-7 year-round |
| UTC-06:00 | America/Chicago | US Central Time, most of Mexico |
| UTC-05:00 | America/New_York | US Eastern Time, Colombia, Peru, Ecuador |
| UTC-03:30 | America/St_Johns | Newfoundland, Canada - Rare 30-minute offset |
| UTC-03:00 | America/Sao_Paulo | Brazil (most), Argentina, Uruguay |
| UTC+00:00 | Europe/London | UK (GMT in winter, BST in summer); Ghana, Iceland always UTC+0 |
| UTC+01:00 | Europe/Paris | Central European Time; most of Western and Central Europe |
| UTC+02:00 | Europe/Helsinki | Eastern Europe, South Africa, Egypt |
| UTC+03:00 | Europe/Moscow | Russia (Moscow), Saudi Arabia, Kenya |
| UTC+04:00 | Asia/Dubai | UAE, Oman, Azerbaijan |
| UTC+05:30 | Asia/Kolkata | India - Single zone for 1.4 billion people, no DST |
| UTC+05:45 | Asia/Kathmandu | Nepal - One of only three 15-minute offsets in use |
| UTC+08:00 | Asia/Singapore | Singapore, Hong Kong, China, Western Australia |
| UTC+09:00 | Asia/Tokyo | Japan, South Korea - No DST observed |
| UTC+09:30 | Australia/Darwin | Australian Central Standard Time - No DST in Northern Territory |
| UTC+10:00 | Australia/Sydney | AEST (winter); shifts to UTC+11 AEDT in summer |
| UTC+12:00 | Pacific/Auckland | New Zealand (NZST); shifts to UTC+13 in NZDT |
| UTC+14:00 | Pacific/Kiritimati | Line Islands, Kiribati - Furthest positive offset on Earth |
Daylight Saving Time Overview
Regions That Observe DST
Approximately 70 countries adjust their clocks for Daylight Saving Time. The practice is most consistent in North America and Europe:
- North America - US, Canada, and Mexico (most states/provinces) spring forward in March and fall back in November.
- Europe - EU member states transition on the last Sunday of March (spring) and last Sunday of October (fall).
- Southern Hemisphere - Australia, New Zealand, Chile, and Paraguay observe DST in opposite months (October–April) since their seasons are reversed.
Regions Without DST
Most of Asia, Africa, and parts of South America keep a fixed UTC offset year-round. Major regions without DST include:
- Japan - Abolished DST after World War II; JST (UTC+9) is permanent.
- China - Uses CST (UTC+8) year-round nationwide since 1991.
- India - IST (UTC+5:30) is fixed; DST was tried briefly but abandoned decades ago.
- Most of Africa - Only Morocco and a few territories observe DST on the continent.
- Russia - Abolished DST in 2014; clocks are now fixed at permanent "summer" offsets.
Common Time Zone Abbreviations
Abbreviations are informal shorthand and are not unique - EST, for example, is used by both the US Eastern time zone and Australian Eastern Standard Time, referring to completely different offsets. Always pair an abbreviation with a UTC offset to avoid ambiguity.
| Abbreviation | Full Name | UTC Offset | DST? |
|---|---|---|---|
| EST | Eastern Standard Time (US) | UTC−5 | Winter only |
| EDT | Eastern Daylight Time (US) | UTC−4 | Summer only |
| CST | Central Standard Time (US) | UTC−6 | Winter only |
| CDT | Central Daylight Time (US) | UTC−5 | Summer only |
| MST | Mountain Standard Time (US) | UTC−7 | Winter only |
| MDT | Mountain Daylight Time (US) | UTC−6 | Summer only |
| PST | Pacific Standard Time (US) | UTC−8 | Winter only |
| PDT | Pacific Daylight Time (US) | UTC−7 | Summer only |
| AKST | Alaska Standard Time | UTC−9 | Winter only |
| AKDT | Alaska Daylight Time | UTC−8 | Summer only |
| HST | Hawaii Standard Time | UTC−10 | Never |
| GMT | Greenwich Mean Time | UTC+0 | No |
| BST | British Summer Time | UTC+1 | Summer only |
| CET | Central European Time | UTC+1 | Winter only |
| CEST | Central European Summer Time | UTC+2 | Summer only |
| EET | Eastern European Time | UTC+2 | Winter only |
| EEST | Eastern European Summer Time | UTC+3 | Summer only |
| MSK | Moscow Standard Time | UTC+3 | Never |
| IST | India Standard Time | UTC+5:30 | Never |
| PKT | Pakistan Standard Time | UTC+5 | Never |
| BST | Bangladesh Standard Time | UTC+6 | Never |
| ICT | Indochina Time | UTC+7 | Never |
| CST | China Standard Time | UTC+8 | Never |
| SGT | Singapore Standard Time | UTC+8 | Never |
| HKT | Hong Kong Time | UTC+8 | Never |
| JST | Japan Standard Time | UTC+9 | Never |
| KST | Korea Standard Time | UTC+9 | Never |
| AEST | Australian Eastern Standard Time | UTC+10 | Winter (Apr–Oct) |
| AEDT | Australian Eastern Daylight Time | UTC+11 | Summer (Oct–Apr) |
| NZST | New Zealand Standard Time | UTC+12 | Winter (Apr–Sep) |
| NZDT | New Zealand Daylight Time | UTC+13 | Summer (Sep–Apr) |
| WAT | West Africa Time | UTC+1 | Never |
| CAT | Central Africa Time | UTC+2 | Never |
| EAT | East Africa Time | UTC+3 | Never |
| SAST | South Africa Standard Time | UTC+2 | Never |
| ART | Argentina Time | UTC−3 | Never |
| BRT | Brasília Time | UTC−3 | Never |
| COT | Colombia Time | UTC−5 | Never |
| PET | Peru Time | UTC−5 | Never |
| CLT | Chile Standard Time | UTC−4 | Winter (May–Aug) |
| GST | Gulf Standard Time | UTC+4 | Never |