Current time and time zone converter

See the exact time now where you are and in the UK, keep a world clock of the places you deal with, and convert any time between time zones, with daylight saving (like GMT and BST) handled for you.

How this time zone converter works

The clock at the top is your device's own clock, shown in the time zone your device is set to. Every other time is worked out from that same moment using the official time zone database (the IANA tz database) that's built into your browser, the same one phones and computers use to change their clocks. It knows each country's rules for daylight saving time, including the dates the clocks change, so you never have to remember whether somewhere is an hour ahead or two.

The clock check asks this site's server for the time a few times in a row. The server runs on Cloudflare, whose clocks are kept in step with atomic time using the Network Time Protocol (NTP). For each reply, the page notes how long the round trip took and assumes the server read its clock halfway through, then uses the quickest reply, since that has the least room for error. The difference between that and your device's clock is how fast or slow your clock is, give or take half the round trip (shown as the "±" figure). Browsers can't talk to NTP servers directly, so this is how web pages check the time; it's usually accurate to within a few hundredths of a second.

To convert a time, the calculator takes the time and date you typed in the zone you chose, finds the exact moment that is in Coordinated Universal Time (UTC), and then shows that moment in every place on your list. If the date is different somewhere, you'll see "+1 day" or "−1 day" next to it.

Two moments a year need care. When the clocks go forward, an hour is skipped, so a time like 01:30 on that night doesn't exist in the UK; the calculator tells you and uses the time an hour later. When the clocks go back, an hour happens twice; the calculator uses the first one.

UK time: GMT and BST

The UK uses Greenwich Mean Time (GMT, the same as UTC) in winter and British Summer Time (BST, one hour ahead, UTC+1) in summer. The clocks change at 1am GMT:

The rule is the last Sunday in March and the last Sunday in October, which is also when most of Europe changes. The United States changes on different dates (the second Sunday in March and the first Sunday in November), so for a few weeks each year the gap between London and New York is four hours instead of five.

Tips for working across time zones

• Say the time zone, not just the time. "15:00 UK time" is clearer than "3pm", and "UK time" covers both GMT and BST so it's right all year.
• Check the date as well as the hour. A Monday morning call from London is Sunday evening on the US west coast and Monday evening in Sydney.
• Watch the weeks around the clock changes. Europe and North America change on different Sundays in spring and autumn, and the southern hemisphere changes the other way round, so regular meetings can move by an hour.
• Keep your own list. Add the cities you work with to the world clock and remove the rest. The list is remembered in this browser.
• Working out hours? For the time between two times on the same clock, use the time difference calculator.

Frequently asked questions

What time zone is the UK in?

The UK is on Greenwich Mean Time (GMT, UTC+0) from the last Sunday in October to the last Sunday in March, and on British Summer Time (BST, UTC+1) the rest of the year. The time zone identifier computers use for it is Europe/London.

Is it GMT or BST now?

The box under the clock at the top of this page says which one the UK is on right now, and the UTC offset.

What's the difference between GMT and UTC?

For everyday use they're the same time. UTC (Coordinated Universal Time) is the world's time standard, kept by atomic clocks. GMT is the UK's winter time zone, and it never changes for summer. BST is GMT plus one hour.

How do I convert a time to another time zone?

Type the time and date, choose the time zone it's in, and the world clock shows that moment everywhere on your list. For example, 15:00 in London on a winter weekday is 10:00 in New York and 02:00 the next day in Sydney.

How do I know if my clock is right?

The "Is your clock right?" check under the clock compares your device's time with an internet time server and tells you how many seconds fast or slow it is. Within half a second is fine for almost everything.

My clock is wrong. How do I fix it?

Turn on automatic date and time. In Windows 11, go to Settings, Time & language, Date & time, turn on "Set time automatically" and press "Sync now". On a Mac, open System Settings, General, Date & Time and turn on "Set time and date automatically". On iPhone and Android it's under Settings, General (or System), Date & time. If the hour is wrong but the minutes are right, check the time zone setting instead.

Why is the clock here different from my phone?

The big clock shows the device you're reading this on. If you're on a computer and it disagrees with your phone, one of them isn't syncing its time. The clock check shows which.

Can I add any city?

You can add any of the world's time zones. The list starts with popular cities, and every other zone is listed by its region and main city, like America/Chicago or Asia/Kolkata. Places in the same zone always show the same time.