Time in Jakarta

Indonesia stretches more than 5,000 kilometers from Sumatra to Papua, so it uses three zones. WIB, UTC+7, covers Sumatra, Java, and West and Central Kalimantan, which together hold most of the population. WITA, Central Indonesia Time, UTC+8, covers Bali, Nusa Tenggara, Sulawesi and South, East and North Kalimantan. WIT, Eastern Indonesia Time, UTC+9, covers Maluku and Papua. The current boundaries date from January 1, 1988, when Bali moved from WIB to WITA. A flight from Jakarta to Bali takes under two hours, but you land with the clock an hour further on.

Proposals to merge the country into a single UTC+8 zone, aligning Jakarta with Singapore and Kuala Lumpur, have been discussed several times, most prominently around 2012, but none has been adopted.

At 6.2° south, Jakarta's day length stays between about 11 hours 46 minutes in June and 12 hours 29 minutes in December. Sunrise moves only between about 5:30 and 6:05 AM, and sunset between about 5:45 and 6:15 PM, so evenings get dark early all year. The city lies near the 105th meridian on which WIB is based, so solar noon falls close to 11:50 AM to 12:05 PM.

Government offices typically work 8:00 to 16:00, and many private firms start at 8:00 or 9:00 because commutes in Jakarta are long. Friday lunch breaks are extended for prayers. The Indonesia Stock Exchange trades from 9:00 with a midday break and closes around 16:00, with a longer break on Fridays. Jakarta is twelve hours ahead of New York in the US winter and eleven in summer, so 8:00 AM in Jakarta is 7:00 or 8:00 PM the previous evening in New York. London is seven hours behind in winter and six in summer. The WIB to EST page lays out every hour.