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World Time Zone Converter – Convert Time Across 400+ Cities & 249 Countries Skip to converter

World Time Zone Converter

Convert time instantly across:

443 cities  ·  249 countries & territories  ·  DST-aware
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Select timezones to convert

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Understanding time zones

What is a time zone?

The Earth rotates 360° every 24 hours — that's 15° per hour. Time zones divide the globe into 24 theoretical slices, each offset from UTC (Coordinated Universal Time) by a whole or half hour. In practice, political borders and geography mean real zones are irregular in shape and number.

38
Distinct UTC offsets in use today
195+
Countries with their own timezone rules
600+
Named zones in the IANA database
26h
Total span: UTC−12 to UTC+14

The official reference is the IANA Time Zone Database (also called the "tz database"), maintained since 1986. It records every timezone rule change in history — including colonial-era adjustments — for every region on Earth. All operating systems and browsers use this database.

UTC offsets explained

How offsets work

Every timezone is expressed as UTC± a number of hours (and sometimes 30 or 45 minutes). To convert between zones, subtract the source offset and add the destination offset to get the correct local time at the destination.

UTC−12:00  Baker Island UTC−8:00  Los Angeles UTC−5:00  New York UTC+0:00  London (winter) UTC+1:00  Paris (winter) UTC+5:30  New Delhi UTC+5:45  Kathmandu UTC+8:00  Beijing UTC+9:00  Tokyo UTC+14:00  Line Islands

Some offsets are 30 or 45 minutes — not a whole hour. India (UTC+5:30), Nepal (UTC+5:45), Iran (UTC+3:30), and Australia's central zones (UTC+9:30 and UTC+10:30) are the most common examples. These exist for historical, political, or geographic reasons.

Daylight saving time (DST)

When do clocks change?

DST advances clocks by 1 hour in spring to shift daylight into evening hours, then turns them back in autumn. First widely adopted during World War I to save fuel, it is now observed by around 70 countries — but the exact dates differ by hemisphere and region.

☀️

Northern hemisphere

Clocks spring forward in March–April and fall back in October–November. Affects the US, Canada, Europe, and parts of the Middle East.

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Southern hemisphere

Opposite seasons — clocks spring forward in September–October and fall back in March–April. Affects Australia, New Zealand, Brazil, and Chile.

2025 DST dates — key regions

United States & Canada Mar 9 → Nov 2
European Union Mar 30 → Oct 26
United Kingdom Mar 30 → Oct 26
Australia (AEDT zones) Apr 6 → Oct 5
New Zealand Apr 6 → Sep 28

Countries that do not observe DST include China, Japan, India, Singapore, most of Africa, and the majority of Southeast Asia. Within the US, Arizona (except the Navajo Nation) and Hawaii also skip it.

Timezone quirks

Unusual and notable cases

China

Spans 5 geographic zones but uses a single offset — UTC+8 — for the entire country, set by Beijing for political unity. The sun rises as late as 10am in western Xinjiang.

Nepal

One of only two regions using a 45-minute offset (UTC+5:45). The other is Chatham Islands, New Zealand (UTC+12:45, or +13:45 during DST).

Kiribati

Line Islands use UTC+14 — the furthest-ahead timezone on Earth. They share a calendar day with UTC−12 despite being geographically close across the date line.

Russia

Has 11 time zones — more than any single country's land mass — spanning UTC+2 (Kaliningrad) to UTC+12 (Kamchatka), a 10-hour internal spread.

France

Has the most time zones of any country (12) due to its overseas territories — from UTC−10 (French Polynesia) to UTC+12 (Wallis & Futuna).

Frequently asked questions

Top questions people search for

Answers to the most common questions about time zones searched on Google.

There are 38 distinct UTC offsets currently in use. However, the IANA timezone database lists over 600 named zones because it tracks historical rule changes per region. The theoretical 24-zone model doesn't match reality — political boundaries, DST rules, and half-hour offsets create far more variation.
DST was introduced during World War I (1916) to reduce artificial lighting demand and save coal. By shifting clocks forward, evening daylight extends, reducing the need for lights in homes and businesses. Its energy-saving benefits today are debated — studies show only marginal reductions, and many countries are considering abolishing it permanently.
GMT (Greenwich Mean Time) is a timezone based on the Royal Observatory in Greenwich, London. UTC (Coordinated Universal Time) is the global scientific time standard maintained by atomic clocks. For everyday purposes they show the same time — UTC+0:00 and GMT+0:00 are identical. The key difference: UTC is a precise standard, GMT is a civil timezone. All tech systems use UTC.
France has the most — 12 time zones — because of its overseas territories spread across the globe, from French Polynesia (UTC−10) to Wallis & Futuna (UTC+12). Russia is second with 11 contiguous zones across its mainland, the most of any single land mass.
No. Only around 70 countries observe DST — less than half the world. Most of Africa, Asia, and equatorial countries (where day length barely varies) do not use it. Notable non-observers: China, Japan, India, Singapore, South Korea, and most of Southeast Asia. Within the US, Arizona and Hawaii skip it too.
The International Date Line (IDL) runs roughly along the 180° meridian in the Pacific Ocean. Crossing it westward moves you forward one calendar day; crossing eastward moves you back one day. The line bends around island nations so that no single country has two different dates within its borders.
All internet servers, databases, and APIs store and transmit time in UTC. UTC never observes DST and has a fixed offset of zero. When you see a timestamp like 2025-06-03T14:00:00Z, the "Z" stands for Zulu — military shorthand for UTC. Your device then converts that to your local timezone for display.
IST is ambiguous — it refers to three different time zones. Indian Standard Time (UTC+5:30) covers India and Sri Lanka and is used by over 1.5 billion people. Irish Standard Time (UTC+1:00) is Ireland's summer time. Israel Standard Time (UTC+2:00) is used in Israel. Always verify the region when interpreting three-letter abbreviations.
Nepal set its timezone at UTC+5:45 in 1986, choosing to differ from neighboring India (UTC+5:30) by 15 minutes — a deliberate assertion of national identity. The offset also puts local noon closer to actual solar noon at Nepal's central meridian. It is one of only a handful of regions using a non-30-minute offset from UTC.
Yes — Eastern Standard Time (EST) is UTC−5:00. However, when the US observes Daylight Saving Time (March to November), clocks move to Eastern Daylight Time (EDT), which is UTC−4:00. "ET" (Eastern Time) is used as a shorthand that covers both EST and EDT depending on the time of year. Three-letter abbreviations like EST, PST, and CST technically refer to standard time only.