Half-Hour and 45-Minute Time Zones: Every One, and Why They Exist
Most of the world’s time zones are a whole number of hours ahead of or behind Coordinated Universal Time (UTC). But about one in five people on Earth live in a place that is offset by a half hour or even 45 minutes. India alone accounts for most of them.
Key facts
- In January 2027, 11 different non-whole-hour offsets are in use, from UTC−9:30 to UTC+13:45.
- India (UTC+5:30) is by far the biggest, with about 1.46 billion people.
- Nepal (UTC+5:45) and New Zealand’s Chatham Islands (UTC+12:45, or +13:45 in summer) are 45 minutes off the hour.
- Lord Howe Island in Australia moves its clocks by just 30 minutes for daylight saving time.
Every half-hour and 45-minute time zone
| Offset from UTC | Where | About how many people |
|---|---|---|
| UTC−9:30 | Marquesas Islands (French Polynesia) | 9,000 |
| UTC−3:30 (−2:30 in summer) | Newfoundland and south-eastern Labrador, Canada | 550,000 |
| UTC+3:30 | Iran | 92 million |
| UTC+4:30 | Afghanistan | 43 million |
| UTC+5:30 | India and Sri Lanka | 1.48 billion |
| UTC+5:45 | Nepal | 30 million |
| UTC+6:30 | Myanmar and the Cocos (Keeling) Islands | 54 million |
| UTC+8:45 | Eucla area, Western Australia (unofficial) | a few hundred |
| UTC+9:30 (+10:30 in summer) | South Australia, Northern Territory and Broken Hill, Australia | 2 million |
| UTC+10:30 (+11 in summer) | Lord Howe Island, Australia | 400 |
| UTC+12:45 (+13:45 in summer) | Chatham Islands, New Zealand | 800 |
Together that’s about 1.7 billion people, roughly a fifth of the world’s population. You can check the current time in any of these places with the search on our world clock.
Why do half-hour time zones exist?
Standard time zones were designed around 15-degree slices of longitude, each one hour apart. But countries choose their own time, and some picked a time that matches the sun in their capital or the middle of the country.
India: one time for a whole subcontinent
India Standard Time is based on the 82.5° east line of longitude, which runs near Mirzapur, close to Prayagraj, in the middle of the country. That line sits exactly halfway between two standard hour zones, so the offset is UTC+5:30. India uses this one time across the whole country, which means the sun rises almost two hours earlier in the north-east than in the far west. Sri Lanka uses the same time.
Nepal: 15 minutes from India
Nepal’s time is based on the longitude of Mount Gaurishankar, near Kathmandu. Since 1986, Nepal has been 5 hours and 45 minutes ahead of UTC, or 15 minutes ahead of India. It is the only country with a 45-minute offset.
Newfoundland: an island with its own time
Newfoundland was its own dominion until 1949 and kept a time based on St. John’s, which sits about halfway between the Atlantic and Eastern time zones. When it joined Canada, it kept its half-hour time. A TV show that airs “at 9, 9:30 in Newfoundland” is a running joke in Canada.
Central Australia: a compromise
South Australia, the Northern Territory and the outback city of Broken Hill use UTC+9:30, halfway between the times in Perth and Sydney. Adelaide moves to UTC+10:30 in summer, while Darwin stays on UTC+9:30 all year.
Half-hour zones that disappeared
Some places have dropped their half-hour time in recent years:
- Venezuela used UTC−4:30 from 2007 to 2016, then went back to UTC−4.
- North Korea used UTC+8:30 from 2015 to 2018, then switched back to match South Korea.
These changes show that time zones are political choices, not just geography.
What half-hour time zones mean for you
If you work with people in India, Iran or Nepal, the half hour catches people out. When it’s 9 AM in New York in January, it’s 7:30 PM in Mumbai and 7:45 PM in Kathmandu. And because India doesn’t use daylight saving time, the difference with North America and Europe changes twice a year. In the winter, New York is 10.5 hours behind India. In the summer, it’s 9.5 hours. See the best times in our guide on when to call India from the US and Canada, or use the time zone converter.
On New Year’s Eve, these places also celebrate at odd moments. India reaches midnight at 6:30 PM in London. See who celebrates the new year first and last.
How we got these numbers
We listed every time zone in the official IANA time zone database (version 2026e) whose offset from UTC isn’t a whole number of hours, in January or July 2027. Populations are rounded estimates from the UN World Population Prospects for countries and from national statistics agencies for regions.
Frequently asked questions
Which countries have half-hour time zones?
India, Sri Lanka, Iran, Afghanistan and Myanmar use half-hour offsets nationwide. Parts of Canada (Newfoundland), Australia (South Australia, the Northern Territory and Lord Howe Island) and French Polynesia (the Marquesas Islands) do too.
Which country has a 45-minute time zone?
Nepal, at UTC+5:45. New Zealand’s Chatham Islands also use a 45-minute offset (UTC+12:45, or +13:45 in summer).
Why is India 30 minutes off?
India’s standard time is based on a line of longitude through the middle of the country, which is exactly halfway between two hour zones.
What time is it in India now?
See the live time in Mumbai, Delhi or Kolkata, or check India Standard Time.
