Scheduling Across Australia: Why One Time Zone Isn't Enough

Australia officially has three time zones. In practice it has up to five, because not all states observe DST and one state sits on a half-hour offset. The tricky part is that the DST transitions run opposite to the Northern Hemisphere — Australian summer is Northern Hemisphere winter — so every relationship between Australian times and other zones has a seasonal component.

Australia’s time zones

The Queensland problem

Queensland doesn’t observe DST. New South Wales and Victoria do. Sydney and Brisbane are both “eastern Australia” — same time in winter, one hour apart in summer (October through April). If you schedule a recurring call with one Sydney contact and one Brisbane contact, it will break every October when Sydney moves to UTC+11 and Brisbane stays at UTC+10.

This trips people up constantly. Before setting any recurring meeting with Australian contacts, check whether they’re in a DST-observing state.

Overlap windows

The gap between San Francisco and Sydney is 18–19 hours depending on the season. There is no same-day usable overlap. For US West Coast and Australian teams, async is the default — there is no realistic recurring synchronous slot.

New York does better. 6–8pm EST lands at Sydney 9–11am AEST — very tight, but it exists.

When scheduling with Australian contacts, always specify the city, not “Australian Eastern time” — that phrase means different things in October for Sydney versus Brisbane. In meetwhen, use Australia/Sydney, Australia/Brisbane, or Australia/Perth directly — the DST difference between Sydney and Brisbane becomes immediately visible.