A world clock for the places you care about
This page shows the current time in several cities at once, as a board of cards you arrange yourself. Each card has the local time, ticking once a second, the date, the UTC offset of the zone at this moment, a sun or moon for day or night, and the difference to the first card. Add up to twelve cities, move them around so your home or your team's main office comes first, and remove the ones you no longer need. The board is useful for distributed teams, for calling family abroad, for following a launch or a match in another part of the world, and for anyone who keeps asking what time it is somewhere else.
How the clocks are computed
Your device keeps one time, the number of seconds since January 1, 1970 in UTC. A local time anywhere is that moment plus the offset of the place's time zone, and the offset depends on the date, because many zones switch between standard and daylight saving time. The page asks the browser's Intl.DateTimeFormat for the local time in each zone, and the browser uses the IANA time zone database it ships with, so the offsets and the daylight saving dates are the same ones your operating system uses. The guide UTC and time zones explained covers the offset arithmetic. The cities on the list are the principal locations of the zones in that database, taken from its zone.tab file, 134 places on every continent.
The difference shown on a card is the gap between its offset and the offset of the first card at this moment, for example 6 h ahead or 5 h 30 min behind. It changes when either place switches its clocks, which is why the same two cities can be 5 hours apart in January and 4 hours apart in late March.
Day and night
The sun and moon icons come from the hour alone: the sun from 6:00 to 17:59 local time, the moon from 18:00 to 5:59. That is enough to see at a glance whether a call lands in someone's evening, but it is not the real daylight, which in Reykjavik or Helsinki varies from a few hours in winter to almost the whole day in summer. For sunrise, sunset and twilight in any of these cities, use the sunrise and sunset calculator, which works from the same city list.
Planning a call with the slider
The question behind most world clock visits is not what time it is now, but what time it will be somewhere else at a given hour here. Drag the slider to a time in your first city, and every card jumps to that moment on today's date, with the date shown so you notice when the call lands on tomorrow in Sydney or yesterday in Honolulu. The seconds are hidden while the slider is active, and Now brings the live clocks back. For a specific future date, or to convert a single time in many zones, the time zone converter takes a date and time of your own; to find an hour that is inside working hours for everyone, the meeting planner lays the whole day out as a grid.
Reading the UTC offset
UTC+9 means the city is nine hours ahead of Coordinated Universal Time, UTC−5 five hours behind it. Most offsets are whole hours, but some are not: Kolkata is on UTC+5:30 all year, Kathmandu on UTC+5:45 and Adelaide on UTC+9:30 or UTC+10:30 depending on the season. The card shows the offset in force right now, so London reads UTC in winter and UTC+1 in summer. Two cities with the same offset show the same time but can still be in different zones with different switching dates.
Limits
- The clocks are only as accurate as your device's clock. A computer that is two minutes slow shows every city two minutes slow.
- The list holds one city per time zone. For a city that is missing, add one in the same zone: the time is identical.
- Day and night come from the hour, not from the sun.
- The slider works on today's date in the first city. Pick another date in the time zone converter.
- Up to 12 cities, so the board stays readable on a phone.
How to use the world clock
- 1Type a city in the Add field and pick it from the list, or type a zone such as Europe/Paris or an abbreviation such as PST.
- 2Use the arrows on a card to move it; the first card is the reference for the differences. Remove a card with the cross.
- 3Switch between 12 h and 24 h and turn seconds on or off.
- 4Drag the slider to see all cities at a chosen time in your first city. Copy the times for a message, or copy a link that opens the same board.
Sources
- IANA Time Zone Database: the city list comes from its zone.tab file; the offsets and daylight saving rules come from the copy of the database in your browser.
Related guides
- Daylight Saving Time 2026: Clock Change Dates by Country
- UTC and Time Zones Explained: Offsets, GMT, Leap Seconds
- US Time Zones by State: Full List and Split States
Frequently asked questions
Is the time shown accurate?
It is your device's clock, converted to each city's time zone. If your phone or computer keeps good time, every clock on the board is right to the second. If the device clock is off, all clocks are off by the same amount. The conversion itself uses the time zone database built into your browser, which knows the rules and the daylight saving dates of every zone.
Does it handle daylight saving time?
Yes. The offsets come from the browser's time zone database for the exact moment shown, so a city that is on summer time shows its summer offset, and the difference between two cities changes on the right dates. The slider works the same way for the chosen time on today's date.
How does the time slider work?
Drag it to a time in your first city, and every other card shows the time there at that same moment, with the date in case it is already tomorrow or still yesterday. That answers questions like what time it is in Tokyo when it is 3 pm in New York. Press Now to return to the live clocks.
What do the sun and moon mean?
A rough day or night marker from the hour alone: the sun from 6:00 to 17:59 local time, the moon from 18:00 to 5:59. It does not use the real sunrise and sunset. For those, the sunrise and sunset calculator has the exact times for every one of these cities.
Can I add a city that is not in the list?
The list holds the main city of every time zone in the IANA database, 134 places. If your city is missing, add the nearest one in the same time zone, or type a zone name like Europe/Paris or an abbreviation like CET and the matching city is added. You can also type a country name for countries with one zone.
Is my list saved anywhere?
Not on a server. Copy link puts the city names, the clock format and the seconds setting into the link, so the same board opens for whoever gets it. Nothing else leaves your browser.