Time Zone Calculator
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How to use the time zone calculator
- Set the date and time you want to convert, or press Now for the current time.
- Check the "from" time zone. It starts as your device's zone; type a city (such as Chicago) or an IANA name (such as America/Chicago) to change it.
- Edit the list of zones to convert to. Add or remove rows as needed; the first one is shown as the main result.
- Read each local time with its date, UTC offset, time zone name and the difference from the original time.
How time zone conversion works
Target time = UTC + offset(target zone, at that instant)
Offsets come from the IANA time zone database and include daylight saving time
Every time zone is defined by its offset from Coordinated Universal Time (UTC), but the offset is not fixed: places that use daylight saving time move their clocks forward in spring and back in autumn, on dates set by local law. The calculator therefore looks up the offset for the exact date and time, using the IANA time zone database built into your browser, converts to UTC, and then to each target zone. Zones are named after a representative city, such as Europe/Paris, because that is how the database tracks each region's history of rule changes.
Worked example
A video call is set for 9:00 AM in New York on Monday, October 19, 2026. New York is on daylight time then, UTC−04:00, so the call starts at 1:00 PM UTC. Adding each city's offset for that moment gives:
| City | Local time | UTC offset |
|---|---|---|
| London | 2:00 PM, Oct 19, 2026 | UTC+01:00 |
| Kolkata | 6:30 PM, Oct 19, 2026 | UTC+05:30 |
| Tokyo | 10:00 PM, Oct 19, 2026 | UTC+09:00 |
| Sydney | 12:00 AM, Oct 20, 2026 (next day) | UTC+11:00 |
UTC offsets of major cities in 2026
Offsets on January 15 and July 15. Where they differ, the city uses daylight saving time; note that the southern hemisphere does so in January.
| City (zone) | January | July |
|---|---|---|
| Honolulu (Pacific/Honolulu) | UTC−10:00 | UTC−10:00 |
| Los Angeles (America/Los_Angeles) | UTC−08:00 | UTC−07:00 (DST) |
| Denver (America/Denver) | UTC−07:00 | UTC−06:00 (DST) |
| Chicago (America/Chicago) | UTC−06:00 | UTC−05:00 (DST) |
| New York (America/New_York) | UTC−05:00 | UTC−04:00 (DST) |
| St. John's (America/St_Johns) | UTC−03:30 | UTC−02:30 (DST) |
| São Paulo (America/Sao_Paulo) | UTC−03:00 | UTC−03:00 |
| London (Europe/London) | UTC+00:00 | UTC+01:00 (DST) |
| Paris (Europe/Paris) | UTC+01:00 | UTC+02:00 (DST) |
| Johannesburg (Africa/Johannesburg) | UTC+02:00 | UTC+02:00 |
| Moscow (Europe/Moscow) | UTC+03:00 | UTC+03:00 |
| Dubai (Asia/Dubai) | UTC+04:00 | UTC+04:00 |
| Karachi (Asia/Karachi) | UTC+05:00 | UTC+05:00 |
| Kolkata (Asia/Kolkata) | UTC+05:30 | UTC+05:30 |
| Kathmandu (Asia/Kathmandu) | UTC+05:45 | UTC+05:45 |
| Bangkok (Asia/Bangkok) | UTC+07:00 | UTC+07:00 |
| Shanghai (Asia/Shanghai) | UTC+08:00 | UTC+08:00 |
| Tokyo (Asia/Tokyo) | UTC+09:00 | UTC+09:00 |
| Sydney (Australia/Sydney) | UTC+11:00 | UTC+10:00 (DST) |
| Auckland (Pacific/Auckland) | UTC+13:00 | UTC+12:00 (DST) |
Daylight saving changes in 2026
Local clock times when the clocks change, from the time zone database. Regions don't change on the same day, which is why gaps between cities shift for a few weeks each spring and autumn.
| Region | Clocks go forward | Clocks go back |
|---|---|---|
| United States (most states) | Sun, Mar 8, 2026, 2:00 AM → 3:00 AM | Sun, Nov 1, 2026, 2:00 AM → 1:00 AM |
| United Kingdom | Sun, Mar 29, 2026, 1:00 AM → 2:00 AM | Sun, Oct 25, 2026, 2:00 AM → 1:00 AM |
| Central Europe | Sun, Mar 29, 2026, 2:00 AM → 3:00 AM | Sun, Oct 25, 2026, 3:00 AM → 2:00 AM |
| Sydney, Melbourne, Canberra | Sun, Oct 4, 2026, 2:00 AM → 3:00 AM | Sun, Apr 5, 2026, 3:00 AM → 2:00 AM |
| New Zealand | Sun, Sep 27, 2026, 2:00 AM → 3:00 AM | Sun, Apr 5, 2026, 3:00 AM → 2:00 AM |
Skipped and repeated times
On the night clocks go forward, a slice of local time never happens: in New York, 2:00 to 2:59 AM is skipped on March 8, 2026. If you enter a skipped time, the calculator moves it forward by the size of the jump (2:30 AM becomes 3:30 AM) and tells you. When clocks go back, the same local times happen twice; the calculator uses the first occurrence and notes the second. This matches the "compatible" rule used by JavaScript's Temporal API.
Tips for scheduling across time zones
- Check the date, not just the time. A late-evening call in the Americas is often the next morning in Asia and Australia.
- Use city names, not abbreviations. "CST" can mean Central Standard Time in North America or China Standard Time, and abbreviations don't say whether daylight time applies.
- Re-check around clock changes. In March and between late October and early November, the gap between Europe and North America changes for a week or more.
- Historic dates follow the database's record of past rules, which is most reliable from 1970 onward.
To work out how long a trip takes, use the time duration calculator with both times converted to one zone, or add a flight time to a departure with the time calculator.
Frequently asked questions
How do I convert a time from one time zone to another?
Turn the local time into UTC by subtracting the zone's UTC offset on that date, then add the other zone's offset. 9:00 AM in New York on October 19, 2026 is UTC−4 (daylight time), so it is 1:00 PM UTC, which is 2:00 PM in London (UTC+1) and 10:00 PM in Tokyo (UTC+9).
Does the calculator handle daylight saving time?
Yes. It uses the IANA time zone database built into your browser, which records when each place changes its clocks. For example, London is usually 5 hours ahead of New York, but only 4 hours ahead for a few weeks a year, such as October 25 to November 1, 2026, because Europe moves its clocks back a week before the United States.
What happens to a time that is skipped or repeated by a clock change?
When clocks go forward, an hour does not exist: 2:30 AM in New York on March 8, 2026 never happens, so the calculator treats it as 3:30 AM daylight time. When clocks go back, an hour happens twice: 1:30 AM on November 1, 2026 is shown as the first occurrence, and the calculator tells you about the second.
What is the difference between UTC and GMT?
UTC (Coordinated Universal Time) is the world's time standard, kept by atomic clocks. GMT (Greenwich Mean Time) is a time zone with a zero offset, used by the UK and some other countries in winter. For everyday conversions they show the same clock time, but GMT is a zone and UTC is the standard that all offsets are measured from.
Why do some places have offsets of 30 or 45 minutes?
Countries choose their own offsets. India uses UTC+5:30 all year, Nepal UTC+5:45, and Newfoundland in Canada UTC−3:30 in winter. Australia's Lord Howe Island even moves its clocks by only 30 minutes for daylight saving. The calculator shows every offset to the minute.