City comparison · time difference and converter
Mombasa is 4 hours behind Jakarta right now. Jakarta sits in Indonesia on Jakarta; Mombasa sits in Kenya on Nairobi. They are roughly 7,440 km apart (4,623 mi), a flight of about 9h 45m. Jakarta's metro holds around 35.4 million people; Mombasa's around 1.2 million.
Slot 1
13:00 / 09:00
Jakarta / Mombasa
Both inside business hoursSlot 2
14:00 / 10:00
Jakarta / Mombasa
Both inside business hoursSlot 3
15:00 / 11:00
Jakarta / Mombasa
Both inside business hoursEach row is one hour in Jakarta. Green rows are inside business hours in both cities; amber means only one side is at their desk; grey rows fall outside business hours in both.
Pancasila Day
Jakarta, Indonesia · Hari Lahir Pancasila
Mon, Jun 1
Madaraka Day
Mombasa, Kenya
Mon, Jun 1
Great-circle distance
7,440 km
(4,623 mi)
Approximate flight
9h 45m
850 km/h cruise + 1h taxi/climb/descent
Jet lag
4h
Roughly 1 day to adjust per timezone crossed
The heatmap gives you the shape of the day. If you need to convert one specific hour — say a customer call or a release window — open the converter with both cities already loaded.
Open in converter →The difference between Jakarta and Mombasa is not really a number, it's a daily rhythm. Mombasa is 4 hours behind Jakarta on the clock today, but the lived version is that Jakarta is ahead in the calendar, so by the time Mombasa comes online, half of Jakarta's day is already gone. That gap, more than the raw offset, is what teams have to design around.
In Jakarta, the working day picks up earliest in the financial districts — Jakarta's downtown core wakes early and breaks for lunch at the usual hour. The mood in Mombasa is its own story: Mombasa settles into the evening at the usual hour, with the local commuter pattern setting the pace. If you are scheduling between the two, the heatmap above marks the rows where both patterns line up.
Daylight saving is the other thing to keep an eye on. Indonesia either observes DST or holds a fixed offset year-round; Kenya either follows its region's DST pattern or stays put all year. When the two changes are weeks apart, the offset between Jakarta and Mombasa is one hour off the usual for that stretch — a cliff that catches recurring calendar invites unless your calendar app rebases them automatically. Pin the meeting to a city, not an offset, and the tool handles the rest.
For travellers, the 9h 45m flight is the short version of the story. The longer one is jet lag: roughly one day of adjustment per timezone crossed, which means a trip across the 4-hour gap costs about 4 groggy days on each side. Pilots and cabin crew swear by morning sunlight and an early walk; whatever your routine, the wall-clock numbers above are the source of truth for your first morning in the new city.