From
GMT
London
Time Zone Converter
GMT to AST Time Zone Converter
Convert GMT to AST with a live clock, current time difference, UTC offsets, and work-hour overlap. AST is 4 hours behind GMT.
To
Atlantic Time
Halifax
When it is 7:30 AM in GMT, it is 3:30 AM in Atlantic Time.
GMT to AST at a glance
Atlantic Time is 4 hours behind GMT. If someone gives you a time in GMT, move the clock by 4 hours to read it in Atlantic Time. A 9:00 AM start in London becomes 5:00 AM in Halifax.
What GMT covers
GMT is commonly used as the United Kingdom time reference. In summer, the UK moves to British Summer Time. It is a familiar baseline for Europe, Africa, and global remote teams.
What Atlantic Time covers
Atlantic Time is used in eastern Canada and parts of the Caribbean. Halifax is a common city reference for it. It matters when scheduling across North America and island markets farther east.
Quick answers
What is the time difference between GMT and AST?
Atlantic Time is 4 hours behind GMT.
What happens to a 3:00 PM meeting in GMT?
It lands at 11:00 AM in AST.
Does daylight saving time matter for GMT to AST?
GMT and Atlantic Time are shown using the offsets that are active right now, so the result already reflects any daylight saving change in effect today.