Time Zone Converter
Local only — nothing is uploaded unless you save or share it.
A time zone converter and world clock — one time, every city at once.
- Set the time and the city it is in — it starts on now, where you are.
- Add the other cities you care about.
- Read the times and dates side by side, and copy the whole list if you need it.
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Use your browser's Share menu, then “Add to Home Screen”.
About this tool
A time zone converter that shows one moment in as many places as you need at once, rather than making you convert twice to answer a question about three cities. Set the time and the city it is in, add the other cities, and every row updates together — with the date beside each, because the answer to “what time is that in Sydney” is very often “tomorrow”. The hard part of this is daylight saving, and it is where hand-made conversions go wrong. Offsets are not properties of a city, they are properties of a city on a date: New York is five hours behind London for most of the year and four hours behind for two weeks in March, because the two countries change clocks on different days. This uses your browser's own copy of the IANA time zone database and asks it about the specific date you picked, so those two weeks are right, and so is the southern hemisphere running the opposite way round. It also tells you when a time does not exist or happens twice. On the night a country springs forward, the hour that is skipped is a real gap — 2:30 that morning is not a time — and on the night it falls back, 1:30 happens twice. Most converters silently pick one and say nothing. Everything runs in your browser, so it works offline and nothing is sent anywhere.
Frequently asked questions
How do I convert EST to CST?
Add both and read them side by side: EST is one hour ahead of CST, all year, because the United States changes clocks on the same date in every zone. That makes est to cst one of the few conversions that really is a fixed number — most are not, which is why this asks about a date rather than storing an offset per city.
Does this handle daylight saving properly?
Yes, and it is the reason to use it rather than adding hours in your head. An offset belongs to a city on a date, not to a city: London is five hours ahead of New York for most of the year and four for about two weeks each March, because Europe and America change clocks on different days. Pick a date in that window and you will see the unusual figure, because the answer comes from the IANA database in your browser for that exact date.
Why does it show a different date for some cities?
Because it genuinely is a different date there. Nine in the morning in London is eight in the evening in Auckland on the same day, but six in the evening in Los Angeles on the day before. The date is printed against every row for exactly this reason — a meeting invitation that is right about the time and wrong about the day is worse than no invitation.
What happens to a time that does not exist?
It is flagged. On the morning a country springs forward, an hour is skipped — in most of the United States, 2:30 in the morning simply did not happen on that date — and on the morning it falls back, 1:30 happens twice, an hour apart. Both are marked here rather than silently resolved, which is what almost every other converter does.
Can I use it as a world clock?
That is what it is when you leave it on the current time: a world clock showing your cities together, updating as the minutes pass. Press the button to jump back to now after you have been looking at some other moment.
Which cities can I add?
Every zone in the IANA database — around four hundred of them, which is every zone any operating system knows about. They are named after cities rather than abbreviations on purpose: “CST” means both Central Standard Time in America and China Standard Time, thirteen hours apart, while “America/Chicago” means exactly one thing.
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