Time Zone Calculator
Compare local times across cities and see when working hours overlap.
You can compare up to 8 cities.
- New YorkUnited States–UTC−5Base
- LondonUnited Kingdom–5 hr aheadUTC+0
- TokyoJapan–14 hr aheadUTC+9
On the map
24-hour planner
Click a cell to set every city to that time.
- Working hours
- Everyone working
- Selected time
Time zones and daylight saving come from data built into your browser. Rules can change, so double-check important dates locally.
Time Zone Calculator
Time Zone Calculator compares local times and time differences across cities on one screen, and finds when working hours overlap.
Time difference = the gap between two cities’ UTC offsets
New York in winter is UTC−5 and London is UTC+0, so New York is 5 hours behind London. Results use the date you choose, so daylight saving is handled for you.
How to use
- Search for the cities you want to compare. The first city is the base.
- Read each city’s local time and its difference from the base city.
- To check another time, enter a date and time or click a cell in the 24-hour planner.
Key terms
UTC (Coordinated Universal Time)
The reference time that local times around the world are set from. UTC−5 means 5 hours behind UTC, and UTC+9 means 9 hours ahead. New York is UTC−5 in winter, so when it’s 15:00 in UTC, it’s 10:00 in New York.
UTC itself has no daylight saving and stays the same all year. Writing a time in UTC instead of a city’s local time avoids confusion across countries.
Daylight saving time
Moving clocks ahead one hour for the warmer months, so the same city can have a different gap by season. U.S. daylight saving runs from the second Sunday in March to the first Sunday in November.
| New York | UTC | Compared with Tokyo |
|---|---|---|
| July | UTC−4 | 13 hours behind |
| December | UTC−5 | 14 hours behind |
Not every zone is a whole number of hours
| Country | UTC | Ahead of New York in winter |
|---|---|---|
| India | UTC+5:30 | 10 hours 30 minutes |
| Nepal | UTC+5:45 | 10 hours 45 minutes |
The day daylight saving starts has a missing hour
2:30 AM on March 8, 2026 doesn’t exist in New York, because clocks jump from 2:00 straight to 3:00. Entering it shows a notice and calculates it as 3:30 AM.
Daylight saving rules can change
Vancouver has stayed on UTC−7 since March 2026 and no longer changes its clocks by season. So in winter, it’s an hour ahead of Seattle, just to the south.
FAQ
What is the time difference between New York and London?
Usually 5 hours, with London ahead. It can briefly differ when the U.S. and U.K. change their clocks on different dates.
Why does the date look different?
A time difference can put a city on another calendar day. When that happens, “Next day” or “Previous day” appears under the time.
What if my city isn’t listed?
Choose another city in the same time zone. For example, Boston matches New York and Dallas matches Chicago, and you can type those names in the search box too.
Does Phoenix change its clocks?
No. Phoenix stays on the same clock all year, so its gap with other U.S. cities changes when they switch.
How do I find a meeting time?
In the 24-hour planner, each column is the same moment everywhere, and dark blue cells are times when every city is within working hours. Cities far apart, like New York and Tokyo, may not overlap at all, so try widening the working hours a little to find the least disruptive time.
Is what I enter saved?
Nothing is sent to a server. So you can pick up where you left off, your cities and working hours are saved in this browser, and a date and time you set are cleared when you close the tab.