Timezone Converter
Convert any time between world timezones. Select your source and destination, enter a time and date, and see the result instantly.
| City | Country | UTC Offset | Abbreviation |
|---|---|---|---|
| Los Angeles | US | UTC-7 | PDT |
| Denver | US | UTC-6 | MDT |
| Chicago | US | UTC-5 | CDT |
| New York | US | UTC-4 | EDT |
| Sao Paulo | BR | UTC-3 | GMT-3 |
| London | UK | UTC+1 | GMT+1 |
| Paris | FR | UTC+2 | GMT+2 |
| Berlin | DE | UTC+2 | GMT+2 |
| Moscow | RU | UTC+3 | GMT+3 |
| Istanbul | TR | UTC+3 | GMT+3 |
| Dubai | AE | UTC+4 | GMT+4 |
| Mumbai | IN | UTC+5:30 | GMT+5:30 |
| Bangkok | TH | UTC+7 | GMT+7 |
| Singapore | SG | UTC+8 | GMT+8 |
| Hong Kong | HK | UTC+8 | GMT+8 |
| Shanghai | CN | UTC+8 | GMT+8 |
| Tokyo | JP | UTC+9 | GMT+9 |
| Seoul | KR | UTC+9 | GMT+9 |
| Sydney | AU | UTC+10 | GMT+10 |
| Auckland | NZ | UTC+12 | GMT+12 |
How Timezone Conversion Works
Every timezone in the world is defined by its offset from Coordinated Universal Time (UTC), the global time standard maintained by a network of atomic clocks. UTC itself does not observe daylight saving time and serves as the fixed reference point from which all other zones are calculated. When you see a timezone described as UTC+5:30, it means that clocks in that zone are five hours and thirty minutes ahead of UTC. Conversely, UTC-8 means clocks are eight hours behind UTC.
Converting a time from one timezone to another is fundamentally an exercise in addition and subtraction. First, you determine the UTC offset of the source timezone. Then you determine the UTC offset of the destination timezone. The difference between these two offsets tells you how many hours (and sometimes minutes) to add or subtract. For instance, if you are converting from Eastern Standard Time (EST, UTC-5) to Central European Time (CET, UTC+1), the difference is six hours. A meeting scheduled at 10:00 AM EST takes place at 4:00 PM CET.
The calculation becomes more concrete when you convert through UTC as an intermediary step. Take the source time, subtract the source UTC offset to arrive at UTC, then add the destination UTC offset to arrive at the target local time. Using the same example: 10:00 AM EST minus the EST offset of -5 gives 10:00 + 5 = 15:00 UTC. Then 15:00 UTC plus the CET offset of +1 gives 16:00 CET, or 4:00 PM. This two-step process through UTC is exactly what computers do internally, and it works reliably for any pair of timezones.
One subtlety that catches people off guard is date changes. When converting across many hours, the destination time may land on a different calendar date than the source. Converting 11:00 PM in New York (EST) to Tokyo time (JST, UTC+9) yields 1:00 PM the next day, because the 14-hour difference pushes the clock past midnight. Always check whether the date changes when converting across large timezone gaps, especially when scheduling international meetings or booking flights.
Common Timezone Conversions
Certain timezone pairs come up far more frequently than others because of the volume of business, travel, and communication between the regions they serve. Understanding the most common conversions by heart can save considerable time and prevent scheduling errors.
EST to UTC (and back): Eastern Standard Time is UTC-5. Add five hours to convert EST to UTC. During Eastern Daylight Time (EDT, March through November), the offset is UTC-4, so add four hours instead. New York, Toronto, Miami, and Atlanta all use this zone.
PST to GMT: Pacific Standard Time is UTC-8, so add eight hours to reach GMT (which aligns with UTC). Los Angeles, San Francisco, Seattle, and Vancouver use PST. During PDT (daylight saving), the offset shrinks to UTC-7. A 9:00 AM PST call is 5:00 PM GMT.
CST to EST: Central Standard Time is UTC-6, one hour behind Eastern. Add one hour to convert CST to EST. Chicago, Dallas, Houston, and Mexico City use CST.
GMT to IST: Indian Standard Time is UTC+5:30. Add five and a half hours to GMT to get IST. This fractional offset means that meetings between London and Mumbai never land on clean hour boundaries, which is a common source of confusion.
EST to JST: Japan Standard Time is UTC+9, a full 14 hours ahead of EST. This enormous gap means that a 9:00 AM Monday meeting in New York falls at 11:00 PM Monday in Tokyo. Many US-Japan teams schedule calls in the early morning (US) or late evening (Japan) as a compromise.
CET to EST: Central European Time is UTC+1, six hours ahead of EST. Most of Western Europe, including France, Germany, Spain, and Italy, uses CET. A noon CET meeting is 6:00 AM EST, which is why transatlantic meetings often happen in the early afternoon European time.
Daylight Saving Complications
Daylight saving time (DST) is the single largest source of timezone conversion errors. When DST is in effect, clocks spring forward by one hour, changing the UTC offset of every zone that observes it. This means the offset difference between two cities is not constant throughout the year. New York and London are five hours apart in winter (EST vs GMT), but only four hours apart in summer when both regions have sprung forward (EDT vs BST). However, the US and UK switch on different dates, creating two brief windows each year where the gap is unexpectedly six hours or four hours.
Not all countries observe daylight saving time. Most of Africa, Asia, and South America remain on standard time year-round. Arizona (except the Navajo Nation) does not observe DST, even though the rest of the US Mountain time zone does. This creates a situation where Arizona matches Pacific Daylight Time in summer but Mountain Standard Time in winter, effectively toggling which neighboring zone it aligns with.
The Southern Hemisphere adds another layer of complexity. Countries like Australia, New Zealand, and parts of South America observe DST on the opposite schedule: clocks go forward in October and back in April. This means the offset between, say, New York and Sydney changes four times per year: once when the US springs forward, once when Australia falls back, once when the US falls back, and once when Australia springs forward. The gap ranges from 14 to 16 hours depending on the time of year.
The safest way to handle daylight saving transitions is to always specify times in UTC or to use an IANA timezone identifier (such as America/New_York or Europe/London) rather than a fixed abbreviation. Abbreviations like EST, CST, and IST are ambiguous (IST can mean Indian, Irish, or Israel Standard Time) and do not encode whether daylight saving is in effect. IANA identifiers carry the full historical and future ruleset for a zone, allowing software to compute the correct offset for any date automatically.
All UTC Offsets
The world's timezones span a range from UTC-12 to UTC+14, covering a total of 26 distinct hours plus several half-hour and quarter-hour offsets. Below is a reference of the major UTC offsets and the regions they serve.
UTC-12:00 — Baker Island, Howland Island (uninhabited US territories). The last places on Earth where any given date exists.
UTC-11:00 — American Samoa, Niue. Also known as Samoa Standard Time.
UTC-10:00 — Hawaii (HAST), Cook Islands, French Polynesia (Tahiti).
UTC-9:00 — Alaska (AKST). Covers most of Alaska except the Aleutian Islands.
UTC-8:00 — Pacific Time (PST): Los Angeles, San Francisco, Seattle, Vancouver, Tijuana.
UTC-7:00 — Mountain Time (MST): Denver, Phoenix, Salt Lake City, Calgary, Ciudad Juarez.
UTC-6:00 — Central Time (CST): Chicago, Dallas, Houston, Mexico City, Winnipeg, Guatemala City.
UTC-5:00 — Eastern Time (EST): New York, Toronto, Miami, Bogota, Lima, Havana.
UTC-4:00 — Atlantic Time (AST): Halifax, Santiago, Caracas, La Paz, Bermuda.
UTC-3:00 — Brasilia Time (BRT): Sao Paulo, Buenos Aires, Montevideo, Greenland (most).
UTC-2:00 — South Georgia, Fernando de Noronha (Brazil). Very few populated areas.
UTC-1:00 — Azores (Portugal), Cape Verde Islands.
UTC+0:00 — GMT / UTC: London (winter), Lisbon (winter), Reykjavik, Accra, Dakar.
UTC+1:00 — Central European Time (CET): Paris, Berlin, Rome, Madrid, Lagos, Algiers.
UTC+2:00 — Eastern European Time (EET): Cairo, Athens, Helsinki, Johannesburg, Istanbul, Kyiv.
UTC+3:00 — Moscow Time (MSK): Moscow, Riyadh, Nairobi, Baghdad, Doha, Minsk.
UTC+3:30 — Iran Standard Time (IRST): Tehran.
UTC+4:00 — Gulf Standard Time (GST): Dubai, Abu Dhabi, Baku, Tbilisi, Mauritius.
UTC+4:30 — Afghanistan Time (AFT): Kabul.
UTC+5:00 — Pakistan Standard Time (PKT): Karachi, Islamabad, Tashkent, Yekaterinburg.
UTC+5:30 — Indian Standard Time (IST): Mumbai, Delhi, Kolkata, Chennai, Colombo.
UTC+5:45 — Nepal Time (NPT): Kathmandu. One of only a few zones with a 45-minute offset.
UTC+6:00 — Bangladesh Standard Time (BST): Dhaka, Almaty, Omsk.
UTC+6:30 — Myanmar Time (MMT): Yangon, Cocos Islands.
UTC+7:00 — Indochina Time (ICT): Bangkok, Jakarta, Ho Chi Minh City, Krasnoyarsk.
UTC+8:00 — China Standard Time (CST): Beijing, Shanghai, Hong Kong, Singapore, Perth, Taipei.
UTC+9:00 — Japan Standard Time (JST): Tokyo, Seoul, Pyongyang, Yakutsk.
UTC+9:30 — Australian Central Standard Time (ACST): Adelaide, Darwin.
UTC+10:00 — Australian Eastern Standard Time (AEST): Sydney, Melbourne, Brisbane, Guam.
UTC+11:00 — Solomon Islands, New Caledonia, Vladivostok.
UTC+12:00 — New Zealand Standard Time (NZST): Auckland, Wellington, Fiji, Kamchatka.
UTC+13:00 — Tonga, Phoenix Islands (Kiribati), Samoa (since 2011).
UTC+14:00 — Line Islands (Kiribati). The first place on Earth to enter any new day.
Frequently Asked Questions
How do I convert EST to UTC?
Eastern Standard Time (EST) is UTC-5. To convert EST to UTC, add 5 hours to the EST time. For example, 2:00 PM EST becomes 7:00 PM UTC. During daylight saving time (second Sunday in March through first Sunday in November), Eastern Daylight Time (EDT) is UTC-4, so you add 4 hours instead. Always check whether DST is in effect for the date you are converting, as this changes the offset by one hour.
What is the difference between GMT and UTC?
GMT (Greenwich Mean Time) and UTC (Coordinated Universal Time) share the same zero offset from the prime meridian, but they are defined differently. GMT is a time zone historically based on solar observations at the Royal Observatory in Greenwich, England. UTC is the modern international standard, maintained by a network of atomic clocks around the world. In practice, the two are interchangeable for everyday timezone conversions. The key difference is that GMT is used as a timezone (the UK uses it in winter), while UTC is a time standard that never changes.
Why do some time zones have 30- or 45-minute offsets?
Most time zones are offset from UTC by whole hours, but several countries adopted non-standard offsets for practical, political, or historical reasons. India chose UTC+5:30 to place the entire country in a single timezone that roughly splits the difference between its eastern and western extremes. Nepal adopted UTC+5:45 to distinguish itself from India. The Chatham Islands (New Zealand) use UTC+12:45. Iran uses UTC+3:30. These fractional offsets allow closer alignment with local solar noon, but they complicate timezone arithmetic since you cannot simply add or subtract whole hours.
When does daylight saving time change the offset?
In the United States, daylight saving time begins on the second Sunday in March (clocks spring forward one hour) and ends on the first Sunday in November (clocks fall back). In the European Union, DST runs from the last Sunday in March to the last Sunday in October. Australia and New Zealand observe DST on the opposite schedule since they are in the Southern Hemisphere: clocks go forward in October and back in April. Many countries, including most of Asia and Africa, do not observe DST at all. The exact transition dates change the offset between any two zones, which is why using IANA timezone identifiers (like America/New_York) is safer than fixed abbreviations.
How do I convert PST to GMT?
Pacific Standard Time (PST) is UTC-8. Since GMT is equivalent to UTC+0, add 8 hours to convert PST to GMT. For example, 9:00 AM PST is 5:00 PM GMT. During Pacific Daylight Time (PDT), which is UTC-7, add only 7 hours. So 9:00 AM PDT becomes 4:00 PM GMT. Always verify whether daylight saving is active for your specific date to ensure the correct offset is applied.
What is the IANA timezone database?
The IANA timezone database, also known as the tz database or Olson database, is the authoritative source for timezone rules used by virtually all computers, phones, and servers. It uses identifiers in the format "Continent/City" (e.g., America/New_York, Asia/Tokyo, Europe/London) and encodes the full history of UTC offsets and daylight saving transitions for every region. Operating systems and programming languages regularly update their copies of this database to reflect new rules passed by governments. Using IANA identifiers rather than abbreviations ensures correct conversions for any date, past or future.