How it works
Pick two cities and this shows how far apart their clocks are right now: for example, “London is 5 hours ahead of New York.” The difference is computed from each city's live UTC offset, so it accounts for daylight saving as it actually stands today, not a fixed textbook number. Fractional zones such as India (+5:30) and Nepal (+5:45) are handled correctly.
Because the two places can change their clocks on different dates, the gap between them isn't constant, so when a change is coming up in the next few months, you'll see a note telling you the new difference and when it takes effect. Everything runs in your browser and nothing is stored; the pair is saved in the link so you can bookmark or share it.
Frequently asked questions
Why does the difference between two cities change during the year?
Countries start and end daylight saving on different dates, and some don't observe it at all. So the gap between, say, London and New York is usually 5 hours but briefly becomes 4 hours each spring and autumn when one has changed its clocks and the other hasn't yet. This tool shows the current gap and flags the next change.
Is it correct for half-hour and 45-minute zones?
Yes. India (+5:30), Nepal (+5:45), parts of Australia and the Chatham Islands are computed at their true offset, so the difference is exact rather than rounded to whole hours.
Which way round is “ahead”?
“Ahead” means the local clock reads a later time. Tokyo is ahead of London because when it's noon in London it's already evening in Tokyo. Use the swap button to flip the direction.
Can I share the result?
Yes: “Copy link” saves the two cities in the URL, and “Copy answer” copies the plain-English sentence to paste into a message.