Which zone this page means. Japan does not observe daylight saving, so JST applies all year. AEST applies in winter; AEDT (UTC+11) applies from the first Sunday in October to the first Sunday in April. Australian seasons are reversed, so summer time runs over the southern summer. Queensland stays on AEST all year.
JST is behind AEST by 1 hours today
On 19 August 2026, Japan Standard Time is on JST at UTC+09:00 and Australian Eastern Standard Time is on AEST at UTC+10:00. The gap between them is 1 hours, with AEST ahead. So 9:00 am in JST is 10:00 am in AEST, and 5:00 pm in JST is 6:00 pm in AEST. Going the other way, see AEST to JST.
The gap is not constant, and that is the part that catches people out
Australian Eastern Standard Time is currently on standard time and changes next on 4 October 2026. Japan Standard Time does not observe daylight saving, so the gap moves only when Australian Eastern Standard Time changes its clocks — twice a year, by one hour.
When you can actually both be at work
Taking a working day as 9:00 am to 5:00 pm local at each end, there are 7 overlapping hours in a normal day. In JST that window runs from 9:00 am to 4:00 pm, which is 10:00 am to 5:00 pm in AEST. Anything outside it needs one side to start early or finish late.
Zone rules are set by legislation and change, sometimes at short notice. This page is built against tzdata 2026a, last reviewed 2026-08-18. Quarterly. Zone rules change by legislation, sometimes at short notice. Version and review date are shown on every zone page. The converter above reads your browser's own copy of the zone database, so if a rule has changed since this page was built the live answer follows the new rule.
Every convention used above — whether the start date counts, how month ends are clamped, which holidays close an office — is written out on the methodology page, including the daylight-saving rules behind the 1-hour gap above.