World Time Zone Converter
Enter any time and see it across 15 major cities instantly. Click a city to copy.
Stays in your browser · Always freeThis converter shows any time across 15 major world cities at once. Enter a time and date, pick your starting timezone, and the grid updates instantly. Daylight Saving Time and historical offsets are handled automatically by your browser's timezone engine - pick a winter date to see standard time, a summer date to see DST.
How time zones and DST actually work
Every place on Earth has an offset from UTC (Coordinated Universal Time, the modern replacement for GMT). New York is normally UTC−5, London is UTC+0, Tokyo is UTC+9, and so on. To find the time difference between two cities, subtract their offsets: Tokyo (+9) minus New York (−5) = 14 hours.
Daylight Saving Time shifts that offset by one hour for part of the year - typically spring through fall in countries that observe it. Most of the US, Canada, Europe, and parts of South America change clocks; most of Asia, Africa, and the Middle East do not. The exact transition dates vary: the US and Canada switch in March and November, Europe in March and October, and the dates aren't aligned, so the time difference between New York and London actually changes by one hour twice a year.
This is why "the time difference is X hours" is often subtly wrong. New York is 5 hours behind London for most of the year, but it's 4 hours behind for two windows in spring and fall when one country has switched and the other hasn't. The converter handles all of this automatically - the answer depends on the specific date you choose.
Common scheduling patterns
9 AM Eastern is 2 PM in London (winter) or 1 PM (summer). A 10 AM ET standup keeps it inside business hours for both teams year-round.
The overlap window is brutal: New York and Tokyo share roughly zero conventional business hours. The least-bad option is 8 AM ET (10 PM Tokyo) or 7 PM ET (9 AM Tokyo next day). Most US-Japan teams pick "morning for one side, evening for the other" and rotate.
10 AM Berlin is 9 AM London is 11 AM Athens - the entire EU is within two hours. Anything between 10 AM and 4 PM Central European Time works for everyone.
Mumbai is 12.5–13.5 hours ahead of Los Angeles depending on DST. A 9 PM IST meeting in Mumbai is 8:30–9:30 AM PST in LA - usable for both sides.