GUIDES · TIME ZONES
Half-hour and 45-minute time zones: where clocks aren’t on the hour
Quick answer
Most places are a whole number of hours ahead of or behind UTC, but some set their clocks 30 or 45 minutes off the hour. By far the biggest is India (UTC+5:30); others include Iran (UTC+3:30), Myanmar (UTC+6:30), Afghanistan (UTC+4:30), Sri Lanka (UTC+5:30) and parts of Australia and Canada. Nepal is one of the few places on a 45-minute offset (UTC+5:45).
Every half-hour and 45-minute time zone
This list covers every place in the IANA time zone database whose clocks are currently set 30 or 45 minutes off the hour, in winter or summer. Where a place uses daylight saving time, both offsets are shown.
| Place | Area | UTC offset |
|---|---|---|
| St. John’s | Newfoundland and southeastern Labrador, Canada | UTC−3:30 / UTC−2:30 (daylight saving) |
| Marquesas Islands | French Polynesia | UTC−9:30 |
| Tehran | Iran | UTC+3:30 |
| Kabul | Afghanistan | UTC+4:30 |
| Mumbai | India | UTC+5:30 |
| Colombo | Sri Lanka | UTC+5:30 |
| Kathmandu | Nepal | UTC+5:45 |
| Yangon | Myanmar | UTC+6:30 |
| Cocos (Keeling) Islands | Australia | UTC+6:30 |
| Eucla | Western Australia–South Australia border (local use) | UTC+8:45 |
| Darwin | Northern Territory, Australia | UTC+9:30 |
| Adelaide | South Australia and Broken Hill, Australia | UTC+9:30 / UTC+10:30 (daylight saving) |
| Lord Howe Island | Australia | UTC+10:30 / UTC+11 (daylight saving) |
| Chatham Islands | New Zealand | UTC+12:45 / UTC+13:45 (daylight saving) |
Lord Howe Island is unusual twice over: it’s on a half-hour offset in winter, and its daylight saving shift is only 30 minutes. Eucla’s UTC+8:45 is used locally by a handful of roadside communities rather than set in law.
Why some places use half hours
A country that sits between two hour zones sometimes splits the difference so that clock time stays closer to the sun across its territory. India’s UTC+5:30 is a compromise for a single national time that runs from Gujarat in the west to Arunachal Pradesh in the northeast. Nepal’s UTC+5:45 follows a meridian through Nepal itself, which puts it 15 minutes ahead of India. Newfoundland, Iran, Afghanistan and Myanmar have kept half-hour offsets for similar reasons.
Iran stopped changing its clocks for daylight saving after 2022, so it’s now on UTC+3:30 all year.
What half-hour zones mean for meetings
When one side is on a half-hour zone, a meeting on the hour for one person starts at half past for the other. India is 10½ hours ahead of New York in the northern winter and 9½ hours in summer, so 9:00 AM in New York is 7:30 PM (winter) or 6:30 PM (summer) in Mumbai.
Mental arithmetic is where mistakes creep in: it’s easy to add 9 or 10 hours and forget the extra half hour. WherOra’s converter works to the minute and its meeting planner moves in 15-minute steps, so :30 and :45 offsets come out exactly. See New York to Mumbai or EST to IST for an hour-by-hour table.
Common questions
Which countries have half-hour time zones?
India, Sri Lanka, Iran, Afghanistan and Myanmar use half-hour offsets all year. Parts of Canada (Newfoundland), Australia (South Australia and the Northern Territory) and French Polynesia (the Marquesas Islands) do too.
Which places use a 45-minute time zone?
Nepal (UTC+5:45) and New Zealand’s Chatham Islands (UTC+12:45, or UTC+13:45 in summer). Eucla in Western Australia uses UTC+8:45 locally, though it isn’t official.
Does India have daylight saving time?
No. India uses India Standard Time (UTC+5:30) all year across the whole country.