How to use the world clock
- Your own clock comes first, outlined in blue. It follows the time zone your device is set to and is named after a major city in that zone.
- Add a city: start typing its name, its country or a time zone — Mumbai, Brazil or Europe/Madrid all work — and pick it from the list, or press Enter for the first match. Besides the cities listed by name, every zone in your browser’s time zone database can be found, about 400 of them.
- Remove a city with the × on its card. Default cities brings back the starting set.
- 24-hour clock switches between 14:30:00 and 2:30:00 PM.
- The page remembers your cities on this device. Copy link copies an address that contains your list, so a colleague opens exactly the same clocks.
What each clock shows
- Time to the second, updated every second.
- Date, marked Tomorrow or Yesterday when that city is already on a different calendar day than you.
- Day or night — dark cards are cities where it is between 6 p.m. and 6 a.m. This is a simple clock-based cue, not the actual sunrise and sunset, which depend on the latitude and the season.
- UTC offset — how far the city’s clocks are from Coordinated Universal Time, with the local abbreviation when your browser has one (EDT, BST, JST…).
- Difference from you — how many hours (and minutes) the city is ahead of or behind your own clock right now.
- Daylight saving time — shown while the city is on summer time.
How the world clock works
Nothing is fetched from a time server. The page reads the current moment from your device’s clock and asks your browser’s built-in time zone database — the IANA tz database that operating systems and browsers ship and keep updated — what the local time is in each zone at that moment. The UTC offset is the difference between that local time and UTC. Daylight saving time is detected by comparing the zone’s offset in January and in July: if they differ and the current offset is the larger one, summer time is in effect. That works in both hemispheres, because summer time always moves clocks forward.
Since every clock is calculated from your device’s clock, they are only as accurate as it is. Phones and computers that set their time automatically are usually within a fraction of a second; if your own clock is off, every city is off by the same amount.
Not every offset is a whole number of hours. India is UTC+05:30, Iran UTC+03:30, Afghanistan UTC+04:30, Myanmar UTC+06:30 and Newfoundland UTC−03:30 in winter; Nepal is UTC+05:45, and New Zealand’s Chatham Islands are UTC+12:45 (+13:45 in their summer). Kiritimati in Kiribati, at UTC+14:00, is the first place on Earth to start each new day.
Worked example: one moment around the world
When it is 9:00 a.m. on Thursday, October 15, 2026, in New York (Eastern Daylight Time, UTC−04:00), it is 13:00 UTC, and the default cities read:
| City | Local time | UTC offset |
|---|---|---|
| Los Angeles | 6:00 a.m. | UTC−07:00 |
| Chicago | 8:00 a.m. | UTC−05:00 |
| New York | 9:00 a.m. | UTC−04:00 |
| São Paulo | 10:00 a.m. | UTC−03:00 |
| London | 2:00 p.m. | UTC+01:00 |
| Paris | 3:00 p.m. | UTC+02:00 |
| Lagos | 2:00 p.m. | UTC+01:00 |
| Dubai | 5:00 p.m. | UTC+04:00 |
| New Delhi | 6:30 p.m. | UTC+05:30 |
| Beijing | 9:00 p.m. | UTC+08:00 |
| Tokyo | 10:00 p.m. | UTC+09:00 |
| Sydney | midnight, Friday, Oct 16 | UTC+11:00 |
Ten days later the picture changes. London and Paris leave summer time on October 25, New York not until November 1, so for one week New York is only four hours behind London instead of five — a classic source of missed meetings.
When the clocks change in 2026
Daylight saving time in the default cities, from the same time zone database (local dates; the change happens in the early morning hours):
| City | Standard time | Summer time | 2026 changes |
|---|---|---|---|
| Los Angeles | UTC−08:00 | UTC−07:00 | Mar 8 (forward 1 hour), Nov 1 (back 1 hour) |
| Chicago | UTC−06:00 | UTC−05:00 | Mar 8 (forward 1 hour), Nov 1 (back 1 hour) |
| New York | UTC−05:00 | UTC−04:00 | Mar 8 (forward 1 hour), Nov 1 (back 1 hour) |
| São Paulo | UTC−03:00 | — | none |
| London | UTC+00:00 | UTC+01:00 | Mar 29 (forward 1 hour), Oct 25 (back 1 hour) |
| Paris | UTC+01:00 | UTC+02:00 | Mar 29 (forward 1 hour), Oct 25 (back 1 hour) |
| Lagos | UTC+01:00 | — | none |
| Dubai | UTC+04:00 | — | none |
| New Delhi | UTC+05:30 | — | none |
| Beijing | UTC+08:00 | — | none |
| Tokyo | UTC+09:00 | — | none |
| Sydney | UTC+10:00 | UTC+11:00 | Apr 5 (back 1 hour), Oct 4 (forward 1 hour) |
The United States moves its clocks on the second Sunday in March and the first Sunday in November; the European Union and the United Kingdom on the last Sundays of March and October. In the southern hemisphere it runs the other way: Sydney’s summer time ends in April and starts again in October. Brazil, India, China, Japan, Nigeria and the United Arab Emirates don’t change their clocks at all.
Tips
- Planning a call for a later date? Use the time zone converter: it applies the daylight saving rules of that date, which may differ from today’s.
- Look for overlapping office hours. With a five-hour gap, a 9-to-5 day in New York and one in London overlap only from 9 a.m. to noon New York time; between New York and New Delhi there is no overlap at all in October.
- Need a reminder? Set the online alarm clock in your own local time once you know when the other city’s meeting starts.
- Your own clock looks wrong? Turn on “Set time zone automatically” in your device’s date and time settings, then reload the page.
Frequently asked questions
Why is my own clock named after a different city?
Browsers know your time zone, not your city, so the first clock is named after a major city in that zone — Chicago for US Central Time, for example. The time is right for everywhere in that zone. If the time itself is wrong, your device’s time zone setting is wrong.
How accurate are the clocks?
As accurate as your device’s clock. The page calculates every city from it with your browser’s time zone database, so a device that sets its time automatically is normally within a fraction of a second.
Can I save or share my list of cities?
Yes. Your cities are remembered on this device the next time you open the page, and Copy link copies an address that opens the same clocks anywhere. Nothing is stored on a server.
Why are some places 30 or 45 minutes off from their neighbors?
Each country picks its own offset from UTC. India Standard Time, UTC+05:30, is the solar time of the 82.5° E meridian near the middle of the country, and Nepal’s UTC+05:45 follows a meridian that runs through Nepal itself.
Does the world clock handle daylight saving time?
Yes. Each clock uses the current rules from your browser’s time zone database, so a city switches to summer time and back on the right day without any change to the page. The card says “Daylight saving time” while it is in effect.
Last updated: October 15, 2026