Travel
The International Date Line: why you can land before you take off
Fly from Tokyo to Los Angeles and you arrive earlier on the clock, on the same date, than when you left. Fly the other way and a whole day disappears. It is all down to one wiggly line in the Pacific. Here is how it works, and how to plan around it.
Key takeaways
- The date line runs roughly along 180° longitude through the Pacific. Crossing it westward adds a day; crossing eastward takes one away.
- It is not set by any treaty: each country chooses which side it is on. Kiribati moved in 1995 and Samoa skipped 30 December 2011.
- Every day, between 10:00 and 12:00 UTC, three different dates are in use on Earth at the same time.
- Samoa and American Samoa are neighbours with the same clock time but dates a day apart.
On this page
What the date line is
The Earth has 24 hours of time zones. Starting from London and going east, the clocks get later; going west, earlier. Somewhere on the far side of the world the two directions meet, and the calendar has to jump by a day. That seam is the International Date Line. It mostly follows the 180° meridian through the middle of the Pacific, but it zig-zags around island groups so that no country is split between two dates.
The line is not defined by any international treaty. Each country decides which date to use, and the line is drawn around those decisions.
Three dates at once
The earliest time zone on Earth is UTC+14 (Kiritimati, in Kiribati) and the latest is UTC−12 (the uninhabited Baker and Howland Islands). That is a 26-hour spread, so for two hours every day, from 10:00 to 12:00 UTC, three different calendar dates are in use at once. Right now:
- KiritimatiKiribati · UTC+14
- UTCCoordinated Universal Time
- Baker IslandUTC−12, uninhabited
Why flights seem to go back in time
When you fly east across the line, the local clock at your destination is many hours behind the one you left, often by more than the flight takes:
| Flight | Leave | Flight time | Arrive |
|---|---|---|---|
| Tokyo → Los Angeles (January) | Tuesday 5:00 PM | about 10 h | Tuesday 10:00 AM |
| Auckland → Honolulu (January) | Tuesday 7:00 PM | about 9 h | Tuesday 5:00 AM |
| Los Angeles → Sydney (October) | Tuesday 10:00 PM | about 15 h | Thursday 7:00 AM |
Worked out for the dates shown; departure and arrival times are local.
Going west is the opposite: you lose a day. Leave Los Angeles on Tuesday night and you land in Sydney on Thursday morning, without living through a Wednesday. Your body only experiences the flight hours; the missing day comes back on the return journey.
Two tips for travellers. Check the arrival date on your booking, not just the time, before you book a hotel or an airport pickup. And for a meeting on arrival, convert it for the destination’s date: “Monday morning in Auckland” is Sunday afternoon in Los Angeles.
Countries that moved the line
Kiribati, 1995. Kiribati is a nation of islands spread across the line, so for years its east and west were on different dates and government offices shared only a few working days a week. At the turn of 1995 the eastern islands switched from UTC−10 and −11 to UTC+14 and +13, putting the whole country on the same date. It also made the Line Islands the first inhabited place to see each new year, including the year 2000.
Samoa and Tokelau, 2011. Samoa traded mostly with Australia, New Zealand and China but sat on the American side of the line, a day behind its partners. At the end of Thursday 29 December 2011, Samoa and Tokelau jumped straight to Saturday 31 December, skipping Friday 30 December altogether. Workers were paid for the missing day.
Samoa and American Samoa: one clock, two dates
Samoa and American Samoa are neighbouring islands a short flight apart. Samoa is on UTC+13 and American Samoa on UTC−11: exactly 24 hours apart. Their clocks show the same time, but on different dates:
- ApiaSamoa · UTC+13
- Pago PagoAmerican Samoa · UTC−11
The same happens across the Pacific: Tonga, Samoa and New Zealand are almost a whole day ahead of Hawaii and American Samoa.
Who sees the new year first, and last
The first inhabited place to reach midnight on 1 January is Kiritimati (Christmas Island) in Kiribati, at UTC+14, followed by New Zealand’s Chatham Islands, and then Tonga, Samoa and New Zealand. The last inhabited places are American Samoa and Niue at UTC−11, about 25 hours after Kiritimati. The uninhabited Baker and Howland Islands, at UTC−12, finish the year last of all.
Frequently asked questions
Do you lose a day crossing the International Date Line?
Flying west, from the Americas towards Asia or Australia, the date jumps forward a day. Flying east, it goes back a day. The time you actually spend travelling is the same.
Why do flights from Asia to the US arrive before they leave?
Because the destination’s clock is many hours behind: Los Angeles is 17 hours behind Tokyo in winter, more than the 10-hour flight, so you land earlier on the clock than you took off.
Why did Samoa skip a day?
To be on the same date as its main trading partners, Australia, New Zealand and China. Samoa went from Thursday 29 December 2011 straight to Saturday 31 December.
Which country sees the new year first?
Kiribati: the Line Islands, including Kiritimati, are on UTC+14, the earliest time zone on Earth.
Sources
- Wikipedia – Time in Kiribati
- Wikipedia – UTC+14:00
- NBC News – Samoa skips Friday in leap across international date line (2011)
- Al Jazeera – Pacific islands lose a day in dateline warp (2011)
- US Department of State – Bulletin 31: International Dateline (2012)
Checked on 30 September 2026. Times on this page are worked out with the IANA time zone database; live clocks use your browser’s copy of it.