A city’s local time means nothing until you know its offset from UTC and whether daylight saving is in play. Every city card on the world clock answers both questions at a glance:

  • The city name and country
  • The current UTC offset (for example, UTC+2 or UTC-5)
  • The live time, updating every second
  • A small icon or label indicating DST status when applicable

Tap or click any city to see more detailed information, including the date DST next changes and the underlying IANA time zone name (like "America/New_York").

The hour-by-hour table gives you a quick visual comparison: each column is a city, each row is an hour of the day. Scan across to see who is in morning, afternoon, or overnight.

Does the world clock update when DST starts or ends?

Yes. The data comes from the IANA time zone database (via Python zoneinfo), the same database used by operating systems, programming languages, and most calendar apps. When a government changes its DST rules or shifts a time zone, the IANA database updates, and the clocks reflect the change within hours.

You do not need to refresh. The live clocks use your browser’s connection to the server to stay synchronized.

DST status is reflected in the current displayed time. If a city is in daylight saving time, the offset shown (and the time itself) already includes the extra hour. New York in July shows UTC-4 (Eastern Daylight Time), not UTC-5 (Eastern Standard Time). The clocks handle this for you.

Cities that span multiple time zones

Some countries have cities in multiple time zones. The three largest by number of zones are:

  • Russia, 11 time zones, from UTC+2 (Kaliningrad) to UTC+12 (Kamchatka)
  • United States, 9 time zones including territories (Atlantic, Eastern, Central, Mountain, Pacific, Alaska, Hawaii-Aleutian, Samoa, Chamorro)
  • Australia, 3 time zones (Western UTC+8, Central UTC+9:30, Eastern UTC+10), plus external territories

The world clock lets you add any city from any zone. If you search for "Portland," you will see both Portland, Oregon (Pacific Time) and Portland, Maine (Eastern Time). The country label and offset distinguish them.

For a full list of all zones and their offsets, see the UTC Offsets: Full List and Range.

Does the world clock adjust for daylight saving?

Yes, automatically. About 70 countries observe DST; the rest do not. Even within countries that do, not all regions participate. For example:

  • United States: Hawaii and most of Arizona do not observe DST. The Navajo Nation in Arizona does.
  • Canada: Saskatchewan stays on Central Standard Time year-round.
  • Australia: Queensland, Western Australia, and the Northern Territory do not observe DST. New South Wales, Victoria, South Australia, Tasmania, and the Australian Capital Territory do.
  • Mexico: Abolished DST nationally in 2022 except for border municipalities near the US.

When DST starts or ends for a city, the offset and time change automatically. Nothing to do. If you are scheduling a recurring meeting across DST transitions, check the hour-by-hour table around the change dates. That is where the shift becomes visible.

For a country-by-country breakdown, see Daylight Saving Time Around the World: Rules by Country.

Adding and removing cities

The world clock starts with a default set of major cities. To add a city:

  1. Type the city name (or airport code) into the search box.
  2. Select the correct city from the dropdown. Results show country and offset to help you pick.
  3. The city appears in the grid and the table.

To remove a city, click the remove button (usually an X or minus icon) on its card.

You can reorder cities by dragging them. The order you set is saved in your browser for your next visit.