Time in Indonesia
The Republic of Indonesia, a country located in Southeast Asia, comprise many islands, prompting the government to recognise three time zones. Western Indonesia Time (Waktu Indonesia Barat, WIB) is seven hours ahead (UTC+07:00) of the Coordinated Universal Time (UTC), used in the islands of Sumatra, Java, and the western half of Kalimantan. Central Indonesia Time (Waktu Indonesia Tengah, WITA) is eight hours ahead (UTC+08:00), used in the eastern half of Kalimantan, as well as all of Bali, the Lesser Sunda Islands, and Sulawesi. Eastern Indonesia Time (Waktu Indonesia Timur, WIT) is nine hours ahead (UTC+09:00), used in the Maluku Islands and Western New Guinea.
Western Indonesia Time UTC offset
In 1908 during the Dutch East Indies colonial era, only Java and the Madura Island were initially given time until 1932, when the government utilised UTC+06:30 up to +09:30. In between those changes in 1918, Central Java (UTC+07:20, now defunct) was the basis for time in select locations: for instance, Padang was 7 minutes behind Central Java. The Japanese occupation of the Indies prompted the simplification of time in Indonesia to just UTC+09:00, also known as the Japan Standard Time. The Dutch reoccupied the country following its 1945 independence with UTC+06:00 up to +09:00 established, but it was reverted to the 1932 system after they recognised Indonesia's sovereignty. The current time zone division is a 1988 revision of a 1964 division, with Bali, West Kalimantan, and Central Kalimantan changing sides. Without any significant season changes, the daylight saving time system is not observed anywhere in Indonesia, as is other Southeast Asian countries.
The history of time divisions[edit]
Early timekeeping[edit]
The first regulation of time was implemented in 1908 at the request of the Staatsspoorwegen Dutch railway company in Java during the time of the Dutch East Indies. The time in Central Java was set at 12 minutes later than the capital, Batavia, which used GMT +7 hours. This regulation, which came into effect on 1 May 1908, applied only to Java and Madura. Time in the rest of the archipelago remained unregulated.[2][3]
Ten years later, on 22 February 1918, time in Padang, Sumatra was set at 39 minutes ahead of Central Java, while time in Palembang was set at 8 hours and 20 minutes ahead of Greenwich Mean Time. Then, on 1 January 1924, times for various locations were set as follows:[2][3]
Proposal for a single time zone[edit]
On 12 March 2012, Coordinating Minister for the Economy Hatta Rajasa said: "According to research, with a single time zone the country could cut costs by trillions of rupiah."[7]Two months later, The Jakarta Post reported that a single time zone using UTC+08:00 may start on 28 October 2012.[8] However in August, the Jakarta Globe reported that the plan was now on hold.[9] In January 2013, a deputy minister said the idea had been abandoned after missing two target dates: 17 August (Independence day) and 28 October 2012 (Youth Pledge day).[10] Later that year, Rajasa claimed that the plan had not been abandoned, although there was no deadline for implementation.[11]
IANA time zone database[edit]
In the IANA time zone database, Indonesia is given four zones in the file zone.tab: Asia/Jakarta serving Sumatra and Java; Asia/Pontianak serving West and Central Kalimantan; Asia/Makassar serving East Kalimantan, South Kalimantan, the Lesser Sunda Islands, and Sulawesi; and Asia/Jayapura serving the Maluku Islands, Papua, and West Papua. The first two zones use WIB, while the third and last use WITA and WIT, respectively.[12]