Sydney
London
Convert AEST to GMT
Australian Eastern Standard Time to Greenwich Mean Time — London is 9 hours behind Sydney
Quick Facts
Time Difference
-9 hours
AEST Full Name
Australian Eastern Standard Time
GMT Full Name
Greenwich Mean Time
AEST to GMT Conversion Table
Related Conversions
About AEST and GMT Time Zones
AEST (Australian Eastern Standard Time) is UTC+10 and covers cities like Sydney, Melbourne, Brisbane. GMT (Greenwich Mean Time) is UTC+0 and covers cities like London, Dublin, Lisbon.
When it's 12:00 PM (noon) in Sydney (AEST), it's 3:00 AM in London (GMT). The time difference between AEST and GMT is 9 hours — London is behind Sydney.
The 10-hour difference makes real-time overlap challenging — early morning calls (7–9 AM AEST) work best.
Daylight Saving Time
AEST observes Daylight Saving Time and becomes AEDT (Australian Eastern Daylight Time) during summer months, shifting clocks forward by 1 hour to UTC+11.
During DST transitions, the time difference between AEST and GMT may shift by ±1 hour. Always verify the current offset above for the most accurate conversion.
Use our world clock tool to compare Sydney and London with a visual timeline, or browse more timezone conversions.
Frequently Asked Questions
What is the time difference between AEST and GMT?
London (GMT) is 9 hours behind Sydney (AEST). The offset is -9 hours.
Is GMT ahead or behind AEST?
GMT is 9 hours behind AEST. AEST is UTC+10 and GMT is UTC+1.
When it's 12:00 PM in Sydney, what time is it in London?
When it's 12:00 PM (noon) in Sydney (AEST), it's 3:00 AM in London (GMT).
When it's 5:00 PM in Sydney, what time is it in London?
When it's 5:00 PM in Sydney (AEST), it's 8:00 AM in London (GMT).
Does AEST change for Daylight Saving Time?
Yes. AEST (Australian Eastern Standard Time, UTC+10) becomes AEDT (Australian Eastern Daylight Time, UTC+11) in summer, shifting clocks forward 1 hour.