Timezone Calculator

Plan international meetings and visualize time differences across the globe with precision.

Your Local Time
00:00:00
Current Date
Friday, April 18
Current Time

Popular World Times

London

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New York

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Tokyo

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Simplify International Meeting Planning

Coordinating across multiple continents can be frustrating due to overlapping time differences, daylight saving adjustments, and obscure GMT offsets. Our free online timezone calculator visually synchronizes multiple cities so you can instantly find overlapping business hours and properly schedule international meetings.

How it works

By searching and adding the cities occupied by your team or clients, you generate a dashboard of world clocks. Simply drag the interactive timeline slider to quickly determine what 10 AM in New York looks like for your colleagues in Tokyo or London. The tool seamlessly handles the math behind UTC variations.

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Major Global Business Corridors & Overlaps

City Pair Standard Difference DST Sensitivity Recommended Working Overlap
London (GMT) ↔ New York (EST) +5 Hours Shifts to 4 hrs in March & Oct 9:00 AM – 12:00 PM EST (2:00 – 5:00 PM GMT)
New York (EST) ↔ San Francisco (PST) +3 Hours Syncs simultaneously 11:00 AM – 5:00 PM EST (8:00 AM – 2:00 PM PST)
London (GMT) ↔ Mumbai (IST) +5.5 Hours (+4.5 BST) India does not observe DST 8:30 AM – 12:30 PM GMT (2:00 – 6:00 PM IST)
San Francisco (PST) ↔ Tokyo (JST) +16 to +17 Hours Japan does not observe DST 4:00 PM – 7:00 PM PST (9:00 AM – 12:00 PM next day JST)

Frequently Asked Questions

What is the time difference between London and New York?

London (GMT/BST) is normally 5 hours ahead of New York (EST/EDT). However, because the US and UK switch to and from Daylight Saving Time on different calendar dates in March and October/November, the gap narrows to 4 hours for approximately two to three weeks each year.

What is the difference between UTC and GMT?

Coordinated Universal Time (UTC) is the high-precision atomic time standard used across computing, aviation, and telecommunications. Greenwich Mean Time (GMT) is an official civil time zone used in the UK and Western Europe during winter months. Both share the same zero-hour offset.

How does this calculator handle Daylight Saving Time (DST)?

The calculator references standard IANA Time Zone Database rules embedded in your browser, automatically calculating seasonal offsets whether a city is currently observing standard time or daylight saving time.

What are the best hours for an overlap meeting between the US West Coast and Europe?

Between San Francisco/Seattle (PST/PDT) and London/Paris (GMT/CET), the optimal overlapping window is 8:00 AM – 10:00 AM Pacific Time, which corresponds to 4:00 PM – 6:00 PM in London and 5:00 PM – 7:00 PM in Central Europe.