The world clock

How to use the the world clock

1. 1

   Search for a city

   Type any city name or country into the search box. All 34,000 cities in the dataset are searchable, so smaller places resolve just as well as capitals — each one carries its own IANA time zone rather than a country-wide assumption.

2. 2

   Build your board

   Add as many cities as you follow. Cards sort themselves west to east by UTC offset, so the board reads like a strip of the globe and the day boundary is obvious at a glance.

3. 3

   Switch between digital and analog

   The toggle above the board swaps every card between a digital readout and an analog dial. Analog makes the relative position of the hands easier to scan when you are comparing six cities at once.

4. 4

   Read the offsets

   Each card shows the city's UTC offset and how far ahead or behind it runs from your own zone, which your browser reports. The day-and-night tint tells you whether it is a reasonable hour to call before you do the arithmetic.

5. 5

   Come back to the same board

   Your city list is saved to this browser's local storage. It is there the next time you open the page, and it never leaves your device.

Why a world clock beats doing the math

Questions & answers

How many cities can I add to the board?

As many as you like. The search covers 34,043 cities across 244 countries and territories, and each one carries its own IANA time zone, so smaller cities are handled as precisely as capitals.

Is my board saved?

Yes, in this browser's local storage. It is restored the next time you open the page on this device and is never uploaded — there is no account and no server-side copy.

Does the clock handle daylight saving time?

Yes. Every clock is computed from the IANA time zone database built into your browser, evaluated for the current instant, so daylight saving is already applied for each city independently — including the weeks when one city has changed its clocks and another has not.

How does it know whether it is day or night in a city?

From the city's real latitude and longitude and the sun's computed elevation at that moment, rather than a fixed rule about hours. That keeps the day-and-night tint correct at high latitudes, where summer daylight can run past midnight.

Does the page track my location?

No. Your browser reports its own time zone so the board can show relative offsets, and that value never leaves the page. There is no geolocation request, and your position is never requested, derived or recorded.