Which countries use a half hour time zone?

India, Sri Lanka, Iran, Afghanistan, Myanmar, central Australia, the Marquesas and the Canadian province of Newfoundland and Labrador, among others. In total 8 distinct offsets ending in 30 minutes are in force right now.

Why does India use UTC+5:30 rather than a whole hour?

Because the country is about two hours wide in solar terms. Choosing either whole hour would leave one end badly out of step with the Sun, so the clock was set on a central meridian and the half hour is what that meridian produced.

Why does Newfoundland have its own half hour?

It set its clock by its own capital's meridian before joining Canada, and has never given it up. It is the only half hour offset in the western hemisphere.

Do half hour zones observe daylight saving?

Some do, including Newfoundland and Lord Howe Island. When they change, the half hour is carried through the change rather than rounded away.

The time zones half an hour off the hour

Cities on a half-hour offset

703

8 distinct UTC offsets currently end in 30 minutes rather than 00, spread across 11 zones. UTC+5:30 carries 548 of our cities on its own, which is more than most whole-hour offsets manage.

Computed at 5 November 2026 at 14:04 UTC. Offsets are read at this instant. The list is stable in practice: none of these zones rounds its half hour away when it changes clocks, and most of them never change clocks at all.

Half-hour offsets

Zones on them

Cities on them

703

Biggest

UTC+5:30

Offsets in force

Every half hour offset in force right now

#	Offset	Zones	Cities we publish	Where
1	UTC-9:30	Pacific/Marquesas	0	Papeete, French Polynesia
2	UTC-3:30	America/St_Johns	1	Canada
3	UTC+3:30	Asia/Tehran	104	Iran
4	UTC+4:30	Asia/Kabul	11	Afghanistan
5	UTC+5:30	Asia/Colombo, Asia/Kolkata	548	India, Sri Lanka
6	UTC+6:30	Asia/Yangon, Indian/Cocos	37	Myanmar
7	UTC+9:30	Australia/Darwin	1	Australia
8	UTC+10:30	Australia/Adelaide, Australia/Broken_Hill	1	Australia

What counts as a half hour offset

Offset modulo sixty, evaluated live

Each of the 419 zones we publish was asked for its offset from UTC in minutes at the instant of this request, and any zone whose offset leaves a remainder of exactly 30 is included. Offsets are then grouped, so the table has one row per offset rather than one per zone, which is the form a reader actually wants: what matters is that a clock reads half past, not which of several identifiers produced it.

The city counts come from our 6,338 city catalogue and should be read as a measure of significant urban population rather than of total population. The catalogue holds settlements above 100,000 people plus 448 smaller ones the site has always published. A zone showing a single city is not a zone with a single town in it.

Because the test is arithmetic on a live offset rather than a stored list, a zone that adopted or abandoned a half hour would appear or disappear here without any change to this page. That has happened within living memory more than once, which is the main argument for computing rather than storing.

India: one clock for three thousand kilometres

UTC+5:30 is the offset most of the world meets, because India keeps it and India is enormous. A single clock covers a country that spans nearly thirty degrees of longitude, which is close to two hours of real solar time, and the half hour is the compromise: rather than choosing between UTC+5 and UTC+6 and making one end of the country badly wrong, India split the difference at a meridian near Allahabad and made both ends moderately wrong instead.

The cost is borne mostly in the northeast, where the Sun rises before five in the morning in summer and sets well before most offices close, a mismatch that has produced a long-running and entirely serious campaign for a separate eastern clock. The clock ahead of the Sun ranking puts numbers on exactly how badly the far end of the country is served.

The other half-hour clocks, and why each exists

Iran at UTC+3:30 and Afghanistan at UTC+4:30 are meridian arguments of the same kind, each country sitting awkwardly between two hour lines and choosing the middle. Myanmar at UTC+6:30 does the same on the far side of India. Australia's central band at UTC+9:30 splits a continent whose eastern and western halves are three hours apart on the Sun, and adding the half hour let a sparsely populated middle avoid being pushed onto either coast's clock.

Newfoundland at UTC-3:30 is the odd one out, and the only half-hour zone in the Americas. It predates the Canadian federal system's tidy hours: the province set its clock from its own capital's meridian in the nineteenth century, joined Canada in 1949 with that clock already in place, and has kept it since. Attempts to round it away have been raised and dropped repeatedly, generally on the grounds that the half hour is by now a piece of identity rather than a scheduling inconvenience. A quarter of an hour further out and it would be on the 45 minute list instead.

All rankings 45 minute zones Clock ahead of the Sun Timezone converter World time zone map

Questions about this ranking

Which countries use a half hour time zone?: India, Sri Lanka, Iran, Afghanistan, Myanmar, central Australia, the Marquesas and the Canadian province of Newfoundland and Labrador, among others. In total 8 distinct offsets ending in 30 minutes are in force right now.
Why does India use UTC+5:30 rather than a whole hour?: Because the country is about two hours wide in solar terms. Choosing either whole hour would leave one end badly out of step with the Sun, so the clock was set on a central meridian and the half hour is what that meridian produced.
Why does Newfoundland have its own half hour?: It set its clock by its own capital's meridian before joining Canada, and has never given it up. It is the only half hour offset in the western hemisphere.
Do half hour zones observe daylight saving?: Some do, including Newfoundland and Lord Howe Island. When they change, the half hour is carried through the change rather than rounded away.