Time zone converter

Every conversion is one subtraction. Each zone is defined by its offset from Coordinated Universal Time, so the gap between two cities is the difference between their two offsets — and the time in the second city is the time in the first plus that gap. Add a city above and it appears alongside yours with the difference already worked out.

Two things make it go wrong by hand. Offsets are not fixed: a city on summer time sits an hour off its winter offset, and countries switch on different dates, so for a few weeks each spring and autumn the usual gap is simply not the usual gap. And not every offset is a whole hour — India runs at UTC+5:30, Nepal at UTC+5:45, parts of Australia at UTC+9:30. The daylight saving dates for every country are listed separately.

The conversions people ask for most

Worked out for right now, with daylight saving already applied where it is in force. The 9:00 column is there because it is the hour most people are converting — the start of someone's working day.

Each row opens the meeting planner for those two cities, where every hour of the day is laid out rather than just one.

Current UTC offsets

Offsets shown for the moment this page was built. The clocks above are live.

The letters are not a reliable way to say it

Most conversions that go wrong go wrong here rather than in the arithmetic. IST is India (UTC+05:30), Israel (UTC+02:00) and Ireland (UTC+01:00) — a spread of four and a half hours. CST is the central United States (UTC−06:00), all of China (UTC+08:00) and Cuba (UTC−05:00). BST is British Summer Time (UTC+01:00) and Bangladesh Standard Time (UTC+06:00). Six abbreviations in common use mean more than one thing, so where it matters, write the offset instead of the letters — the full list of abbreviations has the rest.

The second trap is the date. Converting across nine hours or more usually lands on a different day, which is why every row above says so when it does — 17:00 in London is 02:00 in Sydney, but tomorrow.

Common questions

How do I convert a time from one time zone to another?

Take the difference between the two UTC offsets and add it to the original time. If New York is UTC−4 and Berlin is UTC+2, Berlin is six hours ahead, so 09:00 in New York is 15:00 in Berlin. The converter does this for every city you add at once, and applies daylight saving for the date in question.

Does the converter handle daylight saving time?

Yes. Offsets come from the IANA time zone database through the browser, so a city that is on summer time reports its summer offset. This matters most in the weeks when one country has changed and the other has not, which is when manual conversion usually goes wrong.

What about time zones that are not a whole number of hours?

They are handled the same way. India is UTC+5:30, Nepal UTC+5:45, and parts of Australia UTC+9:30. Converting by whole hours alone gives the wrong answer for roughly a fifth of the world.

Why does my converted time land on a different day?

Because the gap is wider than the hours left in the day. London to Sydney is nine hours, so 17:00 on a London Monday is 02:00 on a Sydney Tuesday. Anything across nine hours or more will usually cross midnight in one direction or the other, which is why a converted time is only complete with its date attached.

What does IST convert to?

It depends which IST. India Standard Time is UTC+05:30, Israel Standard Time is UTC+02:00 and Irish Standard Time is UTC+01:00 — up to four and a half hours apart. CST and BST are ambiguous in the same way. Where the answer matters, use the UTC offset rather than the letters.

Is the difference between two cities always the same?

No. Countries move on and off daylight saving on different dates, so the usual gap is wrong for a few weeks each spring and autumn. London and New York are five hours apart for most of the year, four for one week in March and six for one week in autumn, because the EU changes on the last Sunday in October and the US on the first Sunday in November.

Planning a call rather than converting a single time? The meeting planner shows the overlapping working hours for every city at once.

Times on this page were calculated on 12 September 2026.