# ASEAN Common Time

The ASEAN Common Time (ACT) is a proposal to adopt a standard time for all Association of Southeast Asian Nations member states. It was proposed in 1995 by Singapore, and in 2004 and 2015 by Malaysia to make business across countries easier. The proposal failed because of opposition in Thailand and Cambodia: Thais and Cambodians argued that UTC+08:00 was not better than UTC+07:00, which is the current time zone of their countries.
Currently, there are four different time zones used by ASEAN countries. UTC+06:30 (Myanmar); UTC+07:00 (Cambodia, Laos, Thailand, Vietnam, and Western Indonesia); UTC+08:00 (Brunei, Central Indonesia, Malaysia, Philippines, and Singapore); and UTC+09:00 (Eastern Indonesia).
The proposal would institute UTC+08:00 as the ASEAN Central Time, putting Myanmar at UTC+07:00, and leaving the less populous eastern Indonesia at UTC+09:00. This would result in the vast majority of the region's people and territory lining up at UTC+08:00—in sync with China, Hong Kong, Macau, Taiwan, and Western Australia, while eastern islands of Indonesia would remain at UTC+09:00—in sync with Japan, South Korea, North Korea, East Timor and Palau.
Some regional businesses have already begun adopting the phrase "ASEAN Common Time", also using the abbreviation ACT, in their press releases, communications, and legal documents. The idea has since been under discussion by ASEAN, with Singapore supporting it strongly.

## List

| ASEAN relation | Country | UTC offset | Time Zone Abbreviation | Notes | Ref |
| ASEAN members | Myanmar | +06:30 | MMT | Some experts suggest that moving to UTC+07:00, rather than UTC+08:00, would be a more natural change. | Myanmar Standard Time |
| ASEAN members | Thailand | +07:00 | ICT | Tried unsuccessfully to switch to UTC+08:00 in 2001 by then-Prime Minister Thaksin Shinawatra. The issue remains under discussion. | Time in Thailand |
| ASEAN members | Laos | +07:00 | ICT | | Time in Laos |
| ASEAN members | Vietnam | +07:00 | ICT | From 13 June 1975 after reunification. | Time in Vietnam |
| ASEAN members | Cambodia | +07:00 | ICT | | Time in Cambodia |
| ASEAN members | Indonesia | +07:00 | WIB | A single national time zone of UTC+08:00 has been proposed, however, it is unclear when or if it may be implemented. | Time in Indonesia |
| ASEAN members | Indonesia | +08:00 | WITA | A single national time zone of UTC+08:00 has been proposed, however, it is unclear when or if it may be implemented. | Time in Indonesia |
| ASEAN members | Indonesia | +09:00 | WIT | A single national time zone of UTC+08:00 has been proposed, however, it is unclear when or if it may be implemented. | Time in Indonesia |
| ASEAN members | Singapore | +08:00 | SGT/SST | Followed Malaysia to switch to UTC+08:00 on 1 January 1982, except under Japanese occupation of Singapore during World War II. | Singapore Time |
| ASEAN members | Malaysia | +08:00 | MYT/MST | Peninsular Malaysia switched from UTC+07:30 on 1 January 1982, and East Malaysia uses it since 1933, except under Japanese occupation during World War II. | Time in Malaysia |
| ASEAN members | Brunei | +08:00 | BNT/BDT | | Time in Brunei |
| ASEAN members | Philippines | +08:00 | PHT/PST | First implemented on 1 January 1845 by redrawing the International Date Line. It became permanent on 29 July 1990 when the country ended the use of daylight saving time, then set at UTC+09:00. | Philippine Standard Time |
| ASEAN observer states | Timor-Leste | +09:00 | TLT | | Time in Timor-Leste |
| ASEAN observer states | Papua New Guinea | +10:00 | PGT | | Time in Papua New Guinea |
| ASEAN observer states | Papua New Guinea | +11:00 | BST | | Time in Papua New Guinea |
| ASEAN Plus Three | Japan | +09:00 | JST | | Japan Standard Time |
| ASEAN Plus Three | South Korea | +09:00 | KST | | Time in South Korea |
| ASEAN Plus Three | China | +08:00 | CST | | Time in China |