Frequently Asked Questions
What is a world clock? +
A world clock displays the current time in multiple cities and time zones simultaneously. It helps you coordinate across different regions, schedule international meetings, or simply check what time it is anywhere in the world.
How accurate is this world clock? +
This world clock uses your device's system clock and the Internationalization API (Intl.DateTimeFormat) to calculate time zones. It is as accurate as your device's clock and automatically accounts for Daylight Saving Time (DST) changes.
Can I add my own cities? +
Yes. Use the 'Add City' dropdown to search and add any city from the built-in list of 40+ cities. You can also remove any city by clicking the × button. Your selections are saved in your browser's local storage.
Does it account for Daylight Saving Time? +
Yes. The clock uses your browser's built-in time zone database which automatically handles DST transitions. When a city enters or exits DST, the displayed time adjusts automatically.
What's the difference between 12-hour and 24-hour format? +
12-hour format (AM/PM) is common in the US and UK. 24-hour format is standard in most of Europe, Asia, and military contexts. Toggle between them using the switch at the top.
How many cities can I display at once? +
There is no hard limit. You can add as many cities as you like. The grid layout adapts to show all selected cities and remains readable on both desktop and mobile.
Does this work offline? +
Yes, once the page is loaded, the world clock works entirely offline. It uses your device's local clock and JavaScript's built-in time zone support.
Why might some times be slightly off? +
If the displayed time seems wrong, check that your device's system clock is set correctly and your time zone is configured properly. The world clock derives all times from your device's clock.