Which zone this page means. GMT and UTC are the same offset but not the same thing: GMT is a time zone, UTC is a time standard. The United Kingdom is on GMT in winter and BST (UTC+1) in summer. 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.
GMT is behind AEST by 10 hours today
On 19 August 2026, Greenwich Mean Time is on GMT at UTC+00:00 and Australian Eastern Standard Time is on AEST at UTC+10:00. The gap between them is 10 hours, with AEST ahead. So 9:00 am in GMT is 7:00 pm in AEST, and 5:00 pm in GMT is 3:00 am in AEST. Going the other way, see AEST to GMT.
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. Greenwich Mean 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 0 overlapping hours in a normal day. There is none: the two working days do not touch at all, so any live meeting between Greenwich Mean Time and Australian Eastern Standard Time has to sit outside somebody's normal hours. The table above shows which end has the shorter stretch to give up.
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 10-hour gap above.