As a rough outline, businesses such as airline offices open Mon-Fri 8am-4pm & Sat 8am-noon. Banking hours are Mon-Fri 8am-3pm & Sat 8am-1pm, but banks may not handle foreign exchange in the afternoons or at weekends. Moneychangers usually keep shop rather than bank hours. Post offices operate roughly Mon-Thur 8am-2pm, Fri 8-11am & Sat 8am-12.30pm. Muslim businesses, including government offices , may also close at 11.30am on Fridays, the main day of prayer, and national public holidays see all commerce compulsorily curtailed.

Ramadan , a month of fasting during daylight hours, falls during the ninth Muslim month (starting in November/December/January). Even in non-Islamic areas, Muslim restaurants and businesses shut down during the day, and in staunchly Islamic parts of rural Lombok, Sumatra or Kalimantan's Banjarmasin, you should not eat, drink or smoke in public at this time. Idul Fitri , also called Hari Raya or Lebaran, marks the end of Ramadan and is a two-day national holiday of noisy celebrations.