WorldTimePortal

Time Zones of the World
map, converter & UTC offsets.

Explore every time zone on an interactive world map with a live day/night overlay, convert times between zones, and look up which zone any major city belongs to. Offsets update automatically with daylight saving changes worldwide.

The world, zone by zone

Every colored band is one UTC offset — all 27 hourly zones from UTC−12 to UTC+14, plus the half-hour zones, each 15° of longitude per hour. Hover the map with your mouse — or tap it on a phone — to see the zone, its local time and major cities; click or tap a band to highlight it in the table below. The dark overlay is the night side of Earth right now.

Which time zone is a city in?

Search covers the largest cities in each country: 68 of the world’s best-known cities, from Mumbai and Chicago to Auckland.

Every major time zone and its biggest cities

Time zoneAbbreviationUTC offset (now)Local timeMajor cities

Offsets and local times are computed live from the IANA time zone database — the same source your phone uses — so daylight saving changes anywhere in the world are reflected automatically, the moment they happen.

Understanding time zones around the world

Time zones exist because the Earth rotates 15 degrees per hour, so noon arrives at different times in different places. Before standard time, every town kept its own local solar time — chaos for railways and telegraphs. In 1884 the International Meridian Conference chose Greenwich, London as the prime meridian, and the modern system of 24 hourly time zones measured from Greenwich Mean Time (GMT) was born. Today the global reference is UTC (Coordinated Universal Time), kept by atomic clocks.

Half-hour and 45-minute offsets

In practice the map is messier than 24 neat stripes. Political borders bend zone lines, and many countries use half-hour or 45-minute offsets: India Standard Time is UTC+5:30, Iran UTC+3:30, Afghanistan UTC+4:30, Myanmar UTC+6:30, central Australia UTC+9:30 and Nepal UTC+5:45. The most extreme zones are UTC+14 on the Line Islands of Kiribati — the first place to greet each new day — and UTC−12 on uninhabited Baker and Howland Islands.

Daylight saving time (DST)

Daylight saving time adds another layer. Most of North America and Europe move clocks one hour forward in spring and back in autumn — New York switches between EST (UTC−5) and EDT (UTC−4), London between GMT and BST (UTC+1), and Sydney between AEST (UTC+10) and AEDT (UTC+11). Because the southern hemisphere's summer is opposite the northern one, the gap between, say, London and Sydney swings between 9 and 11 hours over the year. India, Japan, China and most of Africa and Southeast Asia never change their clocks at all.

Time difference between cities

For travelers, remote teams and anyone with friends abroad, the practical questions are always the same: what is the time difference between two cities, what is the current UTC offset, and when is it a reasonable hour to call? The converter and table above answer all three — and because every value is recalculated live from the official IANA time zone database, the answers stay correct even on the weekends when the clocks change. For live clocks in individual cities, see the world clock.

Time zone questions, answered

How many time zones are there in the world?

In theory 24 hourly zones, but the real world uses around 38 different UTC offsets. Several countries use half-hour offsets (India UTC+5:30, parts of Australia UTC+9:30) and Nepal even uses UTC+5:45.

What does UTC mean?

UTC stands for Coordinated Universal Time — the global reference all time zones are defined against. A zone written as UTC+2 is two hours ahead of UTC; UTC−5 is five hours behind.

What is the difference between GMT and UTC?

GMT (Greenwich Mean Time) is the historic time zone of the UK in winter. UTC is the modern atomic-clock standard. They show the same time to the second for everyday use, but UTC is the term used in technology and aviation.

Which countries have the most time zones?

France has the most (12) when overseas territories are counted, followed by the United States (11) and Russia (11). By mainland only, Russia spans the most zones. China is the opposite extreme: one single zone (UTC+8) for the whole country.

Why do time differences change during the year?

Because countries switch to daylight saving time on different dates — or not at all. New York and London are 5 hours apart most of the year, but 4 hours apart for a few weeks in spring and autumn. This page recalculates every offset live, so it is always correct.

Where does a new day begin?

At the International Date Line in the Pacific. Kiritimati (Christmas Island, Kiribati) at UTC+14 is the first place to enter each new day, while Baker Island and Howland Island at UTC−12 are the last.