Indonesia is a group of islands and is very big. It takes the sun about three hours to “travel” from the eats to the west of Indonesia. Therefore it’s not surprising Indonesia uses multiple time zones. The west of Indonesia observes Waktu Indonesia Barat WIB. WIB is UTC +0900. Central Indonesia observes Waktu Indonesia Tengah WITA. WITA is UTC +0800. The east of Indonesia observes Waktu Indonsia Timur WIT. Because Indonesia in on the equator the length of the days is close to constant all year round. There is no need for daylight savings time.