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Time Zone Converter

Convert time between zones, compare cities, and find meeting times.

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Convert a time

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World clock & comparison

Meeting time finder

Working hours (9am–6pm) per city across a 24-hour UTC scale. Green = good for that city. The column shaded across all rows is the best overlap.

Common time zones

CityTime ZoneUTC Offset (standard)
New YorkAmerica/New_YorkUTC-5 (UTC-4 DST)
LondonEurope/LondonUTC+0 (UTC+1 DST)
TokyoAsia/TokyoUTC+9
SydneyAustralia/SydneyUTC+10 (UTC+11 DST)
MumbaiAsia/KolkataUTC+5:30
DubaiAsia/DubaiUTC+4
Los AngelesAmerica/Los_AngelesUTC-8 (UTC-7 DST)
SingaporeAsia/SingaporeUTC+8
ガイド・解説

How time zone conversion works

Every time zone is defined as an offset from UTC (Coordinated Universal Time), the global reference standard. Converting a time between zones means expressing the same instant in two different local offsets. This tool reads the browser's built-in time zone database, so it knows each region's current offset and applies it automatically when you pick two zones or compare cities side by side.

What is UTC?

UTC is the time standard the world sets its clocks by. It does not change with the seasons and has no daylight saving, which makes it the neutral baseline for aviation, computing, and international coordination. Local times are described relative to it, for example UTC-5 (US Eastern Standard Time) or UTC+1 (Central European Time). When everyone references UTC, there is no ambiguity about when an event actually happens.

Daylight saving time is handled automatically

Many regions shift their clocks forward in spring and back in autumn, which changes their UTC offset for part of the year. Because this converter uses live time zone data rather than fixed offsets, it accounts for daylight saving automatically for the date in question, so you do not have to remember who is currently observing it. Note that some places (much of the tropics, and a few others) never change their clocks, because the seasonal daylight difference near the equator is small.

Finding a meeting time across zones

Scheduling across continents is the classic headache this tool solves. Compare the cities involved and look for the window where everyone's working hours overlap. The side-by-side clocks make it obvious when a 9am call for you lands in the middle of the night for someone else, so you can pick a slot that is reasonable for all parties.

最終更新日: 2026年9月

Frequently Asked Questions

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