Jakarta is 3 hours behind Melbourne
Best overlap: 11:00 AM to 6:00 PM in Melbourne is 8:00 AM to 3:00 PM in Jakarta.
Shoot for 11:00 AM to 6:00 PM in Melbourne; your Jakarta colleagues will see that as 8:00 AM to 3:00 PM. Jakarta is 3 hours behind Melbourne, but with 7 hours of common ground you can hold morning or afternoon meetings without anyone working odd hours. For part of the year the maths changes: Melbourne observes daylight saving, Jakarta does not, shifting the overlap by an hour.