Convert a time between time zones
Type a time, pick the zone it is in and the zone you want, and see the time there, both UTC offsets, and when the difference next changes. Daylight saving follows your browser’s time zone data for the date.
- Time there
- 2:00 PM
9:00 AM on September 30, 2026 in New York (US Eastern) is 2:00 PM on Wednesday, September 30, 2026 in London, UK.
- Date there
- Wednesday, September 30, 2026
- The To zone is
- 5 hours ahead
- From zone
- Eastern Daylight Time (EDT), UTC−04:00
- To zone
- British Summer Time (BST), UTC+01:00
- Difference changes next
- 4 hours ahead from Saturday, October 24, 2026, 9:00 PM
Answer for the example date Wednesday, September 30, 2026. It changes to today's date when the page loads.
Time there: 2:00 PM. 9:00 AM on September 30, 2026 in New York (US Eastern) is 2:00 PM on Wednesday, September 30, 2026 in London, UK.
How to calculate
Converts a time and date in one time zone to the time and date in another, with both UTC offsets and when the difference next changes.
Example with the default inputs (Time 09:00, From New York (US Eastern), To London, UK, Date September 30, 2026) on the example date Wednesday, September 30, 2026: 9:00 AM on September 30, 2026 in New York (US Eastern) is 2:00 PM on Wednesday, September 30, 2026 in London, UK.
Method: Find the instant (UTC) at which the From zone’s clocks show the date and time, then read the To zone’s clock at that instant; both offsets come from the browser’s IANA time zone data.
- Zones are IANA tzdata names (tzdata 2026a); the browser supplies their offsets and daylight saving rules, so a rule change arrives with a browser update.
- A time that does not exist in the From zone (skipped when clocks spring forward) has no answer. A time that occurs twice (when clocks fall back) shows both results, earlier first, for every output that differs.
- The difference is the To zone’s UTC offset minus the From zone’s, as “3 hours ahead”, “9 hours 30 minutes behind”, or “the same time”.
- “Difference changes next” is the first moment after the typed time, within 366 days, at which the difference changes: the new difference, then that moment as the From zone’s local date and time (“2 hours ahead from Saturday, October 31, 2026, 11:00 PM”).
- Each zone shows its name and abbreviation from the browser’s Unicode CLDR English names (left out when CLDR has none), then its offset as UTC+hh:mm or UTC−hh:mm.
- Dates from 2000 to 2040 work.
Worked examples
Each example is checked against the calculator on every build.
- Time 09:00, From New York (US Eastern), To London, UK, Date 2026-07-01 gives Time there 14:00, Date there 2026-07-01, The To zone is 5 hours ahead, From zone Eastern Daylight Time (EDT), UTC−04:00, To zone British Summer Time (BST), UTC+01:00, Difference changes next 4 hours ahead from Saturday, October 24, 2026, 9:00 PM.Source: IANA Time Zone Database, tzdata 2026a (https://www.iana.org/time-zones)
- Time 18:00, From New York (US Eastern), To Lord Howe Island, Australia, Date 2026-12-01 gives Time there 10:00, Date there 2026-12-02, The To zone is 16 hours ahead, From zone Eastern Standard Time (EST), UTC−05:00, To zone Lord Howe Daylight Time (LHDT), UTC+11:00, Difference changes next 15 hours ahead from Sunday, March 14, 2027, 3:00 AM.Source: IANA Time Zone Database, tzdata 2026a (https://www.iana.org/time-zones)
Other questions people ask
How do I convert a time between time zones?
Take away the From zone’s UTC offset to get UTC, then add the To zone’s offset. For example, 9:00 AM in New York on July 1 is UTC−04:00, so 13:00 UTC; London is then UTC+01:00, so it is 2:00 PM there.
What happens when the clocks change?
On the day clocks spring forward, an hour of local time is skipped (in the US, 2:00 AM to 2:59 AM), so a time in it does not exist and the converter says so. On the day they fall back, an hour happens twice (1:00 AM to 1:59 AM in the US), so the converter shows both results, earlier first.
Why does the difference between two cities change during the year?
Because their clocks change on different dates, or only one of them changes. New York and London are 5 hours apart for most of the year but 4 hours apart for a few weeks in March and in October to November, because the US and Europe change on different Sundays.
Where do the time zones come from?
From the IANA time zone database, as built into your browser. When a country changes its rules, the new rules arrive with a browser update, so the converter needs no update of its own.