Time Difference: London vs Sydney

London (GMT+1) · Sydney (GMT+10)

London

GMT+1

--:--:--

Sydney

GMT+10

--:--:--

Sydney and London are in the same UTC offset

Time Difference

London Offset

GMT+1

Europe/London

Sydney Offset

GMT+10

Australia/Sydney

Summary

London and Sydney share the same UTC offset

Business Hours Overlap (9 AM – 6 PM)

9 hours overlap during standard business hours in both cities.

London	Sydney	Overlap
9 AM	9 AM	Business hours
10 AM	10 AM	Business hours
11 AM	11 AM	Business hours
12 PM	12 PM	Business hours
1 PM	1 PM	Business hours
2 PM	2 PM	Business hours
3 PM	3 PM	Business hours
4 PM	4 PM	Business hours
5 PM	5 PM	Business hours
6 PM	6 PM	Outside

Did You Know? — London & Sydney

Time Zone Facts: London

•London sits on the Prime Meridian at 0° longitude, which is why Greenwich Mean Time (GMT/UTC+0) became the world's reference timezone in 1884 at the International Meridian Conference.
•The London Stock Exchange opens at 8:00 AM GMT and closes at 4:30 PM GMT, making London's morning the global overlap window where both European and (briefly) US pre-market traders are active.
•At 51.5°N — further north than most of Canada — London receives only about 7.5 hours of daylight at winter solstice but enjoys over 16.5 hours of daylight in midsummer.

Time Zone Facts: Sydney

•Sydney uses AEST (UTC+10) in winter and AEDT (UTC+11) in summer — but because Australia's seasons are reversed, Sydney observes DST from October to April, the opposite of Northern Hemisphere cities.
•The Australian Securities Exchange (ASX) in Sydney opens at 10:00 AM AEST/AEDT and closes at 4:00 PM — it is the first major exchange to open each trading day globally.
•At 33.9°S in the Southern Hemisphere, Sydney has about 9.9 hours of daylight in June (its winter) and 14.4 hours in December (its summer).

Frequently Asked Questions

London and Sydney are in the same time zone offset, so there is no time difference between them.

There are 9 overlapping business hours (9 AM–6 PM) between London and Sydney. Scheduling during those hours ensures both parties are in their working day.

London and Sydney share the same UTC offset (GMT+1), so their workdays are completely synchronized — no conversion needed, identical real-time availability, and deadline alignment is automatic.

London observes GMT+1 (Europe/London). A standard 9:00 AM–6:00 PM workday in London maps to specific UTC hours — use UTC-anchored deadlines when coordinating with London-based teammates to avoid confusion from local clock changes.

Sydney observes GMT+10 (Australia/Sydney). A standard 9:00 AM–6:00 PM workday in Sydney maps to specific UTC hours — use UTC-anchored deadlines when coordinating with Sydney-based teammates to avoid confusion from local clock changes.

If {cityA} and {cityB} follow different DST schedules — common in North America–Europe, Southern Hemisphere, or no-DST pairings — the time difference shifts by 1 hour during each transition. The 1–3 weeks between the two cities' clock-change dates create a 'gap window' that frequently catches teams off guard. The difference displayed here is always live and accounts for current DST status.

The best time to call Sydney from London is during the 9-hour business-hours overlap window, when both cities are within their standard working day (9 AM–6 PM).

When it is midnight (00:00) in London, it is 12 AM in Sydney.

No — London and Sydney share the same UTC offset, so they are always on the same calendar date.

London observes Europe/London (GMT+1). For async-first teams, the most reliable approach is anchoring shared deadlines in UTC rather than any local time, and defining each member's 'availability window' — typically 9:00 AM–6:00 PM Europe/London for London. This eliminates confusion when DST transitions shift local clocks seasonally.

Sydney observes Australia/Sydney (GMT+10). For async-first teams, the most reliable approach is anchoring shared deadlines in UTC rather than any local time, and defining each member's 'availability window' — typically 9:00 AM–6:00 PM Australia/Sydney for Sydney. This eliminates confusion when DST transitions shift local clocks seasonally.

Yes — with 9 hours of overlapping business hours, London and Sydney teams can hold real-time standups and synchronous collaboration daily during that window.