World Clock & Time Zone Planner

This shows the current time in several cities at once, and lets you line up a day across all of them to find an hour that suits everybody. Pick your cities, read the live clocks, then use the planner to see the same hour written in every local time, with working hours and day boundaries marked. Every conversion uses the IANA time-zone database built into your browser, so daylight saving is handled by the same rules the rest of your computer uses, and nothing you choose is sent anywhere.

How to use it

1. Search for a city and add it. Your home city sits first and everything else is measured against it.
2. The live clocks show local time, local date, the UTC offset and whether it is day or night there.
3. The planner lays one day out as a row of hours per city, so you can read the same moment across all of them.
4. Working hours and the point where a city rolls over to the next date are both marked, and the best shared window is worked out for you.
5. Your city list is remembered on this device only. It is never uploaded, because there is nothing here that needs a server.

Examples

• Finding an hour that is inside working hours in New Delhi, London and New York at once
• Checking whether it is already tomorrow in Sydney before sending something
• Working out what 9am in Kathmandu is in Adelaide, when both are on quarter- and half-hour offsets

What this tool cannot do

• The live clocks are only as accurate as your device's own clock. If your computer is a few minutes out, the ticking times are too.
• Historical dates far in the past are converted with today's rules for that zone, which is not always what the clocks actually read at the time.
• It does not know about one-off government changes announced but not yet in your browser's time-zone database.

Frequently asked questions

How do I find a meeting time that works in three countries?

Add all three cities, open the planner, and look for the hours shaded as working time in every row at once. The tool also names the longest shared window for you, so you do not have to scan the grid. If there is no overlap at all it says so, rather than offering you the least bad hour and letting you find out why it was awkward.

Does this handle daylight saving automatically?

Yes, and it does it by asking the time-zone database rather than by storing offsets. That matters because the gap between two cities is not fixed: for about three weeks each spring, London is four hours from New York instead of five, because the two countries change their clocks on different dates. Anything that remembers a single number for a pair of cities is wrong for those weeks.

What about India, Nepal and other half-hour time zones?

They are handled exactly like any other zone, which is less common than it should be. India is five and a half hours ahead of UTC and Nepal is five and three quarters, so when the planner is anchored on New Delhi, Kathmandu reads quarter past the hour all the way across. The hour labels on each row show the real local time rather than rounding it, and a city that crosses midnight mid-column has its date line drawn where it actually falls.

Is the time correct if my computer's clock is wrong?

The conversions are, the live readout is not. Converting a time you give it is pure arithmetic and does not depend on your clock being right, so the planner and the date view stay correct no matter what your computer thinks. The live clocks read from your device, so if its clock is wrong they inherit that. A wrong time zone setting on your device does not affect anything, because every calculation here uses a named zone rather than your system's.

Can I use this offline?

Yes. The time-zone rules are part of your browser, not something we fetch, so once the page has loaded it needs no network at all. You can turn off wifi and keep using it. That also means nothing about which cities you are watching ever leaves your device.