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World Clock

See the current time in major cities across all timezones

What is World Clock?

World Clock is a free online tool that helps you see the current time in major cities across all timezones. It runs entirely in your browser using client-side JavaScript, so your data stays private and never leaves your device.

When to Use

  • Converting between timezones when scheduling international meetings
  • Calculating deadlines, durations, and countdowns for project planning
  • Figuring out date differences for travel, billing, or event planning

How to Use

Enter your input in the field above, adjust any settings if available, and click the action button. Results appear instantly—no page reload, no server wait. All processing happens locally in your browser.

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Deep Dive: How World Clock Works

World Clock is a time management utility that helps you navigate the complexities of dates, timezones, and scheduling—problems that appear simple but hide surprising depth. Time calculations are notoriously tricky in programming: months have different lengths, leap years add an extra day every four years (except century years not divisible by 400), daylight saving time shifts by one hour on different dates in different jurisdictions, and timezone offsets range from UTC-12 to UTC+14. The World Clock handles all these edge cases correctly using the browser's Internationalization API, which draws from the IANA timezone database—the gold standard for timezone data maintained by the internet engineering community. Whether you're scheduling meetings across continents, calculating project deadlines that span DST changes, tracking countdowns to important events, or computing work hours with weekend exclusions, the tool delivers accurate results without requiring you to remember all the edge cases. For remote teams, international businesses, and anyone coordinating across timezones, reliable time tools prevent the costly mistakes that come from timezone confusion.

Pro Tips

  • When scheduling across timezones, always specify the timezone in the meeting invite, not just the time
  • For countdowns, add one extra day as a buffer—things rarely finish exactly on schedule
  • Use UTC as your reference point when coordinating across more than two timezones

Common Mistakes to Avoid

  • Assuming all countries observe daylight saving time—many equatorial and Asian countries do not
  • Scheduling meetings at midnight UTC without checking what local time that is for participants

Frequently Asked Questions

How does the World Clock handle timezone differences and daylight saving?
The World Clock uses the IANA timezone database (via the browser's Intl API) to handle all timezone conversions, including daylight saving time (DST) transitions. It automatically adjusts for DST based on each location's current rules. When planning across DST change dates, results account for the offset shift correctly.
Can the World Clock handle recurring events and exclude weekends/holidays?
The World Clock can calculate durations excluding weekends by default. Some tools let you specify custom non-working days. For holiday exclusions, you may need to manually account for specific dates since holiday calendars vary by country and year. The tool focuses on standard work-week calculations.
Why does the World Clock show a different time than my phone or computer?
Differences can occur if your device's timezone settings are incorrect, if you're comparing across timezones without accounting for the offset, or if your device hasn't synchronized with a time server recently. The World Clock uses your browser's timezone setting—verify it matches your actual location in system preferences.