AST — Atlantic Standard Time
UTC-04:00 · 4 hours behind UTC · DST active
Details
| Abbreviation | AST |
| Full name | Atlantic Standard Time |
| UTC offset | UTC-04:00 |
| IANA identifier | America/Halifax |
| DST status | Active |
| Standard offset | UTC-04:00 |
| DST offset | UTC-03:00 |
| Clocks forward | Sunday, March 8, 2026 |
| Clocks back | Sunday, November 1, 2026 |
Countries Using AST
Current offset differs from the label
AST is listed as UTC-04:00, but the live IANA zone America/Halifax is currently UTC-03:00. This usually happens during daylight saving time.
Time Difference from AST
| City | Difference |
|---|---|
| New York | +1h |
| Chicago | +2h |
| Los Angeles | +4h |
| London | -4h |
| Paris | -5h |
| Moscow | -6h |
| Dubai | -7h |
| Mumbai | -8h 30m |
| Bangkok | -10h |
| Shanghai | -11h |
| Tokyo | -12h |
| Sydney | -13h |
| Auckland | -15h |
Using AST in practice
Planning notes for business hours, handoffs, and recurring meetings in this timezone.
Right now
It is currently morning in AST, which is inside a normal workday. Standard business-hour checks should use 9:00 AM-5:00 PM local time.
Best overlap
The best listed workday overlap is with New York: 10:00 AM-5:00 PM AST equals 9:00 AM-4:00 PM there.
Recurring events
This zone observes daylight saving time, so recurring meetings can shift by one hour for people outside the same DST rule.
| Market | AST | Their time |
|---|---|---|
| New York | 10:00 AM-5:00 PM | 9:00 AM-4:00 PM |
| Chicago | 11:00 AM-5:00 PM | 9:00 AM-3:00 PM |
| London | 9:00 AM-1:00 PM | 1:00 PM-5:00 PM |
| Los Angeles | 1:00 PM-5:00 PM | 9:00 AM-1:00 PM |
| Paris | 9:00 AM-12:00 PM | 2:00 PM-5:00 PM |
| Moscow | 9:00 AM-11:00 AM | 3:00 PM-5:00 PM |
Convert AST to Other Time Zones
About AST (Atlantic Standard Time)
AST (Atlantic Standard Time) is a time zone with a UTC offset of -04:00, meaning it is 4 hours behind UTC. The IANA timezone database identifies it as America/Halifax. It is used in 3 countries, including Brazil, Chile, United States.
This time zone observes daylight saving time. During standard time, the offset is UTC-04:00. When DST is active, clocks are advanced by one hour to UTC-03:00. In 2026, DST begins on Sunday, March 8, 2026 and ends on Sunday, November 1, 2026. DST is currently active.
Major cities in AST include Halifax, Dartmouth.
Frequently Asked Questions
What is AST?
AST stands for Atlantic Standard Time. It is 4 hours behind UTC (UTC-04:00). The IANA timezone identifier is America/Halifax.
What is the current time in AST?
The current AST time is shown at the top of this page and updates every second. AST is UTC-04:00, which is 4 hours behind UTC.
Does AST observe daylight saving time?
Yes. When DST is active, the offset changes from UTC-04:00 to UTC-03:00. In 2026, clocks spring forward on Sunday, March 8, 2026 and fall back on Sunday, November 1, 2026.
What countries use AST?
Countries and regions using AST include Brazil, Chile, United States.
How do I convert AST to my local time?
Use our time zone converter to convert AST to any other time zone. You can also check the time difference table on this page which shows the offset between AST and 13 major world cities.