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About time-zones.org — World Time Tools

time-zones.org is a free world time reference covering 433 cities, timezone conversion, calendars, sunrise times, moon phases, and date calculators.

What is time-zones.org?

time-zones.org is a free, fast, and ad-light reference for anyone who works across timezones or needs accurate time information anywhere in the world. Every tool on the site updates live in your browser — no apps, no accounts, no data collected.

Our Tools

World Clock

Live clocks for 433 cities across every IANA timezone. Filter by region or search by city name, country, or timezone. Each city has its own dedicated page showing the current local time, UTC offset, DST status, and today's sunrise and sunset.

Timezone Converter

Convert any date and time between two timezones instantly. Handles daylight saving time automatically so the result is always accurate.

Meeting Planner

Schedule meetings across up to 8 timezones on a shared 24-hour timeline. Business hours are highlighted in green so you can find the overlap at a glance.

Calendar

Full monthly calendar with public holidays for the United States, United Kingdom, Canada, Australia, and Germany. Toggle ISO week numbers and print a clean single-page calendar directly from your browser.

Date Calculator

Three tools in one: calculate the duration between two dates in years, months, weeks, and days; add or subtract a period from any date; count business days between two dates excluding weekends and public holidays.

Countdown Timer

Count down to any event. Set a custom name and date, or pick from upcoming public holidays with one click.

Sun & Moon

Sunrise, sunset, solar noon, and day length for 433 cities worldwide, calculated using your chosen city's exact coordinates. Includes a 30-day moon phase calendar and current moon illumination.

Our Data

  • City and timezone data — 433 cities, 365 unique IANA timezones, sourced from the dr5hn/countries-states-cities-database.
  • Holiday data — 2026 public holidays for US, UK, CA, AU, and DE, sourced from the Nager.Date API.
  • Sun and moon calculations — Powered by SunCalc, an open-source astronomy library.
  • Timezone arithmetic — Powered by Luxon, which uses the browser's built-in IANA timezone database.

Built With

time-zones.org is a static site built with Hugo, served as plain HTML, CSS, and JavaScript. There is no server, no database, and no backend — every calculation happens in your browser.

Contact

Found a bug or have a suggestion? We'd love to hear from you. Open an issue or reach out via the links in the footer.