Time difference calculator
How many hours ahead or behind is another city? Pick two places for the live difference, a conversion table and the hours you can both work.
40.7494°, -73.9819° · America/New York
51.5000°, -0.1167° · Europe/London
Hour-by-hour conversion table
| New York | London |
|---|
Popular time differences
- New York and London
- New York and Paris
- New York and Tokyo
- New York and Los Angeles
- New York and Sydney
- New York and Dubai
- New York and Singapore
- New York and Hong Kong
- New York and Toronto
- New York and Chicago
- New York and San Francisco
- New York and Delhi
- New York and Mumbai
- New York and Bangkok
- New York and Berlin
- London and Paris
- London and Tokyo
- London and Los Angeles
- London and Sydney
- London and Dubai
- London and Singapore
- London and Hong Kong
- London and Toronto
- London and Chicago
- London and San Francisco
- London and Delhi
- London and Mumbai
- London and Bangkok
- London and Berlin
- Paris and Tokyo
US city time differences
- New York and Houston
- New York and Philadelphia
- New York and Honolulu
- New York and Anchorage
- New York and Denver
- New York and Miami
- New York and Seattle
- New York and Boston
- New York and Washington, D.C.
- New York and Las Vegas
- New York and Phoenix
- New York and Atlanta
- New York and Dallas
- Los Angeles and Houston
- Los Angeles and Philadelphia
- Los Angeles and Honolulu
- Los Angeles and Anchorage
- Los Angeles and Denver
- Los Angeles and Miami
- Los Angeles and Seattle
How time differences work
Every civil time zone is defined as an offset from Coordinated Universal Time (UTC). The difference between two places is simply the difference between their offsets at that moment. Half-hour and quarter-hour zones (India at UTC+5:30, Nepal at UTC+5:45, Newfoundland at UTC−3:30) produce differences such as 9.5 or 10.75 hours.
To convert a specific meeting time rather than “now”, use the time zone converter; for three or more people use the meeting planner.
Frequently asked questions
How do I calculate the time difference between two places?
Find each place’s current UTC offset and subtract one from the other. Tokyo is UTC+9 and London is UTC+1 in British summer time, so Tokyo is 8 hours ahead; in winter London is UTC+0 and the gap grows to 9 hours. The calculator above does this using each zone’s rules for today.
Why does the time difference change during the year?
Because of daylight saving time. Places that change their clocks do so on different dates (the US in March and November, Europe in March and October, the Southern Hemisphere in roughly October and April), and many places never change at all. Each change can widen or narrow the gap by an hour.
What does “ahead” and “behind” mean?
A place that is ahead has a later clock time at the same moment. Places to the east are generally ahead: when it is 09:00 in New York it is 14:00 in London, so London is 5 hours ahead.
Can the time difference be more than 12 hours?
Yes. Offsets run from UTC−12 to UTC+14, so the gap between, say, Honolulu (UTC−10) and Kiritimati in Kiribati (UTC+14) is 24 hours: the same clock time, but a different calendar day.
What is the best time to call someone in another time zone?
Look for the shaded rows in the hour-by-hour table, where both places are within 09:00–17:00. If there is no overlap, early morning for the place that is behind usually meets late afternoon for the place that is ahead. The meeting planner handles three or more cities.
More CoordKit tools
- Distance between cities
- Great circle distance
- Flight distance
- Midpoint calculator
- Bearing calculator
- Sunrise & sunset times
- Golden hour & blue hour
- Coordinates finder
- Reverse geocoding
- Batch geocoding
- Coordinate converter
- Hemisphere finder
- Antipode map
- World clock
- Time zone converter
- Time difference
- Meeting planner
- Jet lag calculator