The Federated States of Micronesia, a country in Oceania consisting of around 607 islands, observes two time zones,[1] in its western part, and in its eastern part.[2] Micronesia does not have an associated daylight saving time.[3]
Micronesia lies just north of the equator, west of the international date line.[4]
As part of New Spain, Caroline Islands belonged to Captaincy General of the Philippines, which used the date of the western hemisphere and had the same day of the week as the Americas. After Mexico gained its independence from Spain on September 27, 1821, Caroline Islands began using the same day of the week as Asia and to follow the eastern hemisphere at the end of 1844. The switch was achieved by removing Tuesday, December 31, 1844 from the calendar, so Monday, December 30, 1844 was immediately followed by Wednesday, January 1, 1845. That change redrew the International Date Line from being west to east of the whole archipelago to realign itself from American to Asian dates.
Before time zones were introduced, every place used local observation of the sun to set its clocks, which meant that every location used a different local mean time based on its longitude. For example, Kolonia, a coastal town and the capital of Pohnpei State at the time, at longitude 158°13′E, had a local time equivalent to UTC-13:27:08 under the date of the western hemisphere and UTC+10:32:52 under the eastern hemisphere.
In August 1945, Chuuk Time (CHUT) was established as UTC+10 and Pohnpei Standard Time (PONT) as UTC+11.
| Period in use | Time offset from GMT/UTC | Name of time |
|---|---|---|
| before Monday, December 30, 1844 | GMT−13:52:52 (in Colonia, Yap) | Local Mean Time |
| GMT−13:27:08 (in Kolonia, Pohnpei) | ||
| GMT−14:50 (in Ngulu Atoll, the westernmost point) | ||
| GMT−13:08 (in Kosrae, the easternmost point) | ||
| Wednesday, January 1, 1845 – 1900 | GMT+10:07:08 (in Colonia, Yap) | Local Mean Time |
| GMT+10:32:52 (in Kolonia, Pohnpei) | ||
| GMT+09:10 (in Ngulu Atoll, the westernmost point) | ||
| GMT+10:52 (in Kosrae, the easternmost point) | ||
| 1901 – September 1914 | GMT+10:00 (in Colonia, Yap) | +10 |
| GMT+11:00 (in Kolonia, Pohnpei) | +11 | |
| October 1914 – January 1919 | GMT+09:00 | +09 |
| February 1919 – 1936 | GMT+10:00 (in Colonia, Yap) | +10 |
| GMT+11:00 (in Kolonia, Pohnpei) | +11 | |
| 1937 – March 1941 | GMT+10:00 | +10 |
| April 1941 – July 1945 | GMT+09:00 | +09 |
| August 1945 – present | GMT/UTC+10:00 (in Colonia, Yap) | Chuuk Time |
| GMT/UTC+11:00 (in Kolonia, Pohnpei) | Pohnpei Standard Time | |
In the IANA time zone database, Micronesia is given the following three time zones:[5]