By Tim King · Updated 19 September 2026

Time Zone Converter

Any Time Between Any Two Cities

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Date

Time

From zone

To zone

Result

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How the Time Zone Converter works

This time zone converter handles daylight saving on the date you pick. Pick a date, a time and the two cities, and this converts the one into the other using the real daylight saving rules for each place on that exact date. It also tells you the offset between the two zones and the matching UTC time, so you can paste an unambiguous timestamp into an invite.

Most time zone mistakes are not arithmetic mistakes. The subtraction is trivial; what goes wrong is that a city's offset from UTC is not a constant, and the abbreviation people quote does not identify a place.

Time zone converter: a zone is a set of rules, not a number

Sydney is UTC+10 for part of the year and UTC+11 for the rest. Brisbane, six hundred kilometres north, is UTC+10 all year. For half the year they are the same, and for the other half they are an hour apart, which is why "eastern Australia" is not a usable answer to "what time is it there". This converter works from the zone identifiers — the Australia/Sydney and America/New_York names maintained in the IANA database — because those carry the whole history of when each place changed its clocks, including changes that happened only once. Choosing a fixed offset like GMT+10 instead is what produces a correct answer in March and a wrong one in November.

"AEST" is ambiguous for half the year

Australian Eastern Standard Time is UTC+10, but during daylight saving Sydney is on AEDT, UTC+11 — and plenty of people, calendar apps and email footers keep writing AEST anyway. The same trap sits in the northern hemisphere with EST and EDT, and CST means Central Standard Time in North America, China Standard Time in Asia, and Cuba Standard Time in the Caribbean. If you are writing a time down for someone else, write the city or the UTC offset. Never rely on the three letters alone.

One hour each year does not exist

When the clocks jump forward, the local time goes straight from 2:00 to 3:00 and every wall-clock time in between never happens. Enter one of them here and you will get a note saying so, along with the moment the clock actually reached — because a missing time cannot be converted, it can only be nudged. This is why a recurring 2:30 am job runs zero times on that date, and why servers are configured in UTC.

One hour each year happens twice

When the clocks go back, 2:30 am comes round, the clocks return to 2:00, and 2:30 am comes round again — two different instants with the same name, an hour apart. Asked to convert one, this tool uses the first of the two and tells you it did. That repeated hour is the reason a log file can appear to go backwards in time, and the reason overnight shifts on that date are paid nine hours for an eight-hour roster.

Time difference between cities: the date matters as much as the time

Northern and southern hemispheres change their clocks at opposite ends of the year, so the gap between London and Sydney is nine hours, ten hours or eleven depending on the week. A recurring meeting fixed to one city's clock drifts against every other city's clock four times a year. Fix the meeting to the zone the attendees actually live in, and check it again on the change dates.

UTC converter: standard and daylight offsets for common cities

The offset a city uses depends on the date. This table shows each city's UTC offset in January and in July of 2026; cities with the same figure in both columns do not observe daylight saving.

City	January	July
London	UTC+0	UTC+1
Dublin, Lisbon	UTC+0	UTC+1
Berlin, Paris, Rome	UTC+1	UTC+2
Athens, Helsinki	UTC+2	UTC+3
Istanbul	UTC+3	UTC+3
Moscow	UTC+3	UTC+3
Dubai	UTC+4	UTC+4
Karachi	UTC+5	UTC+5
Kolkata	UTC+5:30	UTC+5:30
Bangkok, Jakarta	UTC+7	UTC+7
Singapore, Hong Kong	UTC+8	UTC+8
Perth	UTC+8	UTC+8
Tokyo, Seoul	UTC+9	UTC+9
Brisbane	UTC+10	UTC+10
Sydney, Melbourne	UTC+11	UTC+10
Auckland	UTC+13	UTC+12
Honolulu	UTC−10	UTC−10
Los Angeles, Vancouver	UTC−8	UTC−7
Denver	UTC−7	UTC−6
Phoenix	UTC−7	UTC−7
Chicago	UTC−6	UTC−5
New York, Toronto	UTC−5	UTC−4
São Paulo	UTC−3	UTC−3
Johannesburg	UTC+2	UTC+2

What time is it in Sydney when it is noon in London or New York?

Because the two hemispheres change clocks at opposite ends of the year, the gap between Sydney and a northern city takes three different values across 2026:

Date	Sydney ahead of London	Sydney ahead of New York	London ahead of New York
15 January	11 h	16 h	5 h
15 March	11 h	15 h	4 h
15 April	9 h	14 h	5 h
15 July	9 h	14 h	5 h
15 October	10 h	15 h	5 h
15 November	11 h	16 h	5 h

Noon in London is 11 pm in Sydney in January and 9 pm in July. Even London and New York, both in the northern hemisphere, drift to a four-hour gap for a couple of weeks in March because the United States moves its clocks forward before Europe does.

Time zone conversion worked examples

The formula: target time = source time − source UTC offset + target UTC offset.

First example. 9:00 in London on 15 July is UTC+1, so 8:00 UTC. Sydney is UTC+10 in July, so it is 18:00 there the same day.

Second example. 9:00 in New York on 15 January is UTC−5, so 14:00 UTC. Tokyo is UTC+9, so it is 23:00 there the same day.

How many time zones are there? 24 hour-wide bands in theory, but about 38 offsets in use, because of half-hour and 45-minute zones such as India at UTC+5:30 and Nepal at UTC+5:45.

FAQ

Why does the time difference between two cities change during the year?

Because each city starts and ends daylight saving on its own dates, and some cities never observe it at all. London and Sydney are ten hours apart for most of the year, nine hours apart when Britain is on summer time but Australia is not, and eleven hours apart in the opposite gap.

What is the difference between AEST and AEDT?

AEST is Australian Eastern Standard Time, UTC+10, used in winter. AEDT is Australian Eastern Daylight Time, UTC+11, used from early October to early April in New South Wales, Victoria, the ACT and Tasmania. Queensland stays on AEST all year, so it does not use AEDT at all.

What happens if I enter a time that daylight saving skipped?

The tool tells you. On the morning the clocks jump forward, the hour between 2:00 and 3:00 local time simply does not occur, so there is no instant to convert. The result is shown for the moment the clock reached after the jump, with a note explaining the shift.

Why should I use UTC instead of a local time?

UTC never changes offset and never has daylight saving, so a UTC timestamp means exactly one instant everywhere in the world. That is why servers, logs, flight schedules and APIs use it. Send someone a UTC time and there is nothing left to misread; send them "3pm" and there is plenty.

How do I convert time between time zones by hand?

Convert the local time to UTC by subtracting that city's offset on that date, then add the destination city's offset on the same date. Noon in Sydney in July is UTC+10, so 02:00 UTC; London is UTC+1 in July, so 03:00. Get either offset wrong for the date and the answer is off by an hour, which is why the converter looks the rules up rather than asking you for a number.

Why is London five hours ahead of New York most of the year but four in March?

The United States starts daylight saving on the second Sunday of March and the United Kingdom on the last Sunday of March, so for two or three weeks New York has moved forward and London has not. The same thing happens in reverse for a week at the start of November.