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Time Zone Calculator

Convert a meeting time, flight time or call time from one time zone to another, with daylight saving time handled for the exact date, and see what time it is in major cities at that moment.

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How to use the time zone calculator

  1. Enter the date and the time you want to convert. The date matters, because daylight saving time starts and ends on different days in different countries.
  2. Choose the from time zone: the place where that time applies. "Your time zone" uses the setting on your device.
  3. Choose the to time zone.
  4. Read the converted time, the time difference between the two places, and a table of the same moment in more than 40 cities, from Honolulu to Auckland.

How time zones are converted

Every conversion goes through Coordinated Universal Time (UTC), the reference time that doesn't change with the seasons:

UTC time = local time in the "from" zone − that zone's UTC offset on that date Target time = UTC time + the "to" zone's UTC offset on that date Time difference = offset of the "to" zone − offset of the "from" zone

An offset is how far a zone is ahead of or behind UTC: Karachi is UTC+5, Mumbai is UTC+5:30, and New York is UTC−5 in winter and UTC−4 in summer. The calculator looks up the offset for the exact date in the IANA time zone database built into your browser, the same data that phones and computers use to set their clocks, so daylight saving time is applied automatically.

Worked example

The calculator opens with 9:00 AM today in New York, converted to Karachi. Taking October 29, 2026:

  • New York is on daylight saving time until November 1, 2026, so its offset is UTC−4.
  • UTC time: 9:00 AM + 4 hours = 1:00 PM UTC.
  • Karachi is UTC+5 all year, so 1:00 PM + 5 hours = 6:00 PM the same day.
  • Karachi is 9 hours ahead of New York on this date.

From November 2026 New York goes back to UTC−5, so the same 9:00 AM becomes 2:00 PM UTC and 7:00 PM in Karachi. The difference grows to 10 hours, even though nothing changed in Pakistan.

At that same moment on October 29, 2026, it's 6:00 AM in Los Angeles, 1:00 PM in London, 4:00 PM in Riyadh, 5:00 PM in Dubai, 6:30 PM in Mumbai, 10:00 PM in Tokyo, and midnight going into Friday in Sydney.

Daylight saving time catches people out

Countries that change their clocks don't all do it on the same day, so the gap between two cities can change by an hour for a few weeks each year:

Region Clocks go forward Clocks go back
United States and Canada 2nd Sunday in March (March 8, 2026) 1st Sunday in November (November 1, 2026)
United Kingdom and European Union Last Sunday in March (March 29, 2026) Last Sunday in October (October 25, 2026)
Southeast Australia (Sydney, Melbourne) 1st Sunday in October (October 4, 2026) 1st Sunday in April (April 5, 2026)
Pakistan, India, UAE, Saudi Arabia, Japan, China No daylight saving time –

Between March 8 and March 29, 2026, New York is only 4 hours behind London instead of the usual 5, and the same happens again from October 25 to November 1. If you set up a weekly call across the Atlantic, check it during those weeks. On the night clocks go forward, one hour simply doesn't exist (2:30 AM on March 8, 2026 in New York), and on the night they go back, one hour happens twice. The calculator tells you when you've entered one of those times.

Frequently asked questions

What is the time difference between Pakistan and the USA?

It depends on the US time zone and the season. Pakistan is UTC+5 with no daylight saving time, so it's 9 hours ahead of New York in summer and 10 hours ahead in winter. It's 12 hours ahead of Los Angeles in summer and 13 in winter.

What is the difference between GMT and UTC?

For everyday use they show the same time. UTC is the modern scientific standard kept by atomic clocks, while GMT is the time zone used in the UK in winter. In summer the UK moves to British Summer Time (UTC+1), so London isn't on GMT all year.

Why do some places have half-hour or 45-minute offsets?

Some countries chose an offset that matches their position on the globe or their politics better than a whole hour would. India is UTC+5:30, Iran is UTC+3:30, Nepal is UTC+5:45 and Adelaide is UTC+9:30 in winter. The calculator handles these exactly.

Will the result be right for dates in the future?

Yes, as long as the country doesn't change its rules. Governments sometimes add or drop daylight saving time with a few months' notice. Your browser's time zone data is updated with system updates, so very recent changes may take a little while to appear.

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Results are calculated in your browser. Double-check anything important before you rely on it. See our disclaimer.