How many clocks can I add?

Up to ten. The limit keeps the grid readable on mobile and prevents localStorage from growing unnecessarily.

Do my clocks stay after I close the tab?

Yes. Selections are saved to localStorage under the key ttk-world-clocks and restored on every visit. Clearing your browser storage will reset the default clock set.

How often does each clock update?

Once per second. The page uses a single requestAnimationFrame loop that checks whether the second has changed and only repaints when it has.

Can I see historical times, not just the current moment?

No — the World Clock always shows the current moment across zones. For historical or future conversions, use the Timezone Converter.

World Clock

Track the current time in multiple cities and time zones at a glance.

How to use the World Clock

Add the cities or timezones you care about and watch the current local time in each one update live, second by second.

Press the Add clock button to open the timezone picker.
Type to search — you can filter by city name (for example "Tokyo") or by IANA zone (for example "Asia/Tokyo").
Pick a zone from the list. It appears as a new clock card showing the local time, date, and current UTC offset.
Add up to ten clocks. Each card has a remove button if you no longer need that zone.
Your selection is saved to your browser under the key ttk-world-clocks, so the same clocks reappear the next time you visit.

Frequently asked questions

How many clocks can I add?: Up to ten. The limit keeps the grid readable on mobile and prevents localStorage from growing unnecessarily.
Do my clocks stay after I close the tab?: Yes. Selections are saved to localStorage under the key ttk-world-clocks and restored on every visit. Clearing your browser storage will reset the default clock set.
How often does each clock update?: Once per second. The page uses a single requestAnimationFrame loop that checks whether the second has changed and only repaints when it has.
Can I see historical times, not just the current moment?: No — the World Clock always shows the current moment across zones. For historical or future conversions, use the Timezone Converter.