Time Zones of Indonesia

Basic time zone concepts

Rules currently in force

SectionStandard TimeArea CoveredZone Name
WestUTC+7Sumatera, Java, Western BorneoAsia/Jakarta
CentralUTC+8Sulawesi, Lesser Sunda Islands, Bali, Eastern BorneoAsia/Ujung_Pandang
EastUTC+9Irian Jaya, MalukuAsia/Jayapura


Indonesian time zones follow provincial boundaries. Western Borneo consists of the provinces of Kalimantan Barat and Kalimantan Tengah; Eastern Borneo is Kalimantan Selatan and Kalimantan Timur.

Time zone history

Source: This information was adapted from the tz database.

Zone NameStandard TimeFinal Date
Asia/JakartaLocal Mean Time1867-08-10 00:00
UTC+7:07:121923-12-31 23:47:12
UTC+7:201932-11-01 00:00
UTC+7:301942-03-23 00:00
UTC+9:001945-08-01 00:00
UTC+7:301948-05-01 00:00
UTC+8:001950-05-01 00:00
UTC+7:301964-01-01 00:00
Asia/Ujung_PandangLocal Mean Time1920-01-01 00:00
UTC+7:57:361932-11-01 00:00
UTC+8:001942-02-09 00:00
UTC+9:001945-08-01 00:00
Asia/JayapuraLocal Mean Time1932-11-01 00:00
UTC+9:001944-01-01 00:00
UTC+9:301964-01-01 00:00


1988-01-01 00:00 Western Borneo switched from Asia/Ujung_Pandang to Asia/Jakarta zone.

Time zone names

The following names and abbreviations are standard in Indonesia.

TimeAbbrevNameEnglish equivalent
UTC+7WIBWaktu Indonesia BaratWestern Indonesia Standard Time
UTC+8WITAWaktu Indonesia TengahCentral Indonesia Standard Time
UTC+9WITWaktu Indonesia TimurEastern Indonesia Standard Time


More formally, the names can be written "Waktu Indonesia Bagian Barat", etc. ("bagian" = "region").

The following names and abbreviations for Indonesian time zones come from the tz database. They were created by a contributor. Don't assume that these names, or anything like them, have ever been used officially in Indonesia.
The western zone was called Jakarta Mean Time (JMT) from 1924 to 1932, and Java Time (JAVT) thereafter.
The central zone was called Macassar Mean Time (MMT) from 1932 to 1942, and Borneo Time (BORT) thereafter. (Note: the name of the city of Macassar was changed to Ujung Pandang around 1970.)
The eastern zone was called Jayapura Time (JAYT) from 1944 onward.
UTC+9, as used during World War II, was called JST.
UTC+9:30, as used in the eastern zone from 1944 to 1963, was called CST. There is no indication what this stood for.

Reference: Time Genie 

Back to main statoids page Last updated: 2007-12-31
Copyright © 2001, 2003, 2007 by Gwillim Law.