ET to AST Time Converter
AST is 1 hour ahead of ET. The US East Coast is currently on EDT (UTC-4:00), and Atlantic Canada and the Caribbean are currently on ADT (UTC-3:00).
Best Time to Call Between ET and AST
Both zones are inside normal business hours between 9:00 AM and 4:00 PM ET — that's 10:00 AM to 5:00 PM AST. That's a 7-hour window.
both at work ET only AST only neither — hours along the strip are ET.
Common Times Converted
ET on the left, AST on the right.
ET to AST: Full 24-Hour Conversion Table
Shaded rows are working hours; the darker shade marks the hours when both zones are at work.
| ET | AST | Working hours |
|---|---|---|
| 12:00 AM | 1:00 AM | — |
| 1:00 AM | 2:00 AM | — |
| 2:00 AM | 3:00 AM | — |
| 3:00 AM | 4:00 AM | — |
| 4:00 AM | 5:00 AM | — |
| 5:00 AM | 6:00 AM | — |
| 6:00 AM | 7:00 AM | — |
| 7:00 AM | 8:00 AM | — |
| 8:00 AM | 9:00 AM | AST only |
| 9:00 AM | 10:00 AM | Both zones |
| 10:00 AM | 11:00 AM | Both zones |
| 11:00 AM | 12:00 PM | Both zones |
| 12:00 PM | 1:00 PM | Both zones |
| 1:00 PM | 2:00 PM | Both zones |
| 2:00 PM | 3:00 PM | Both zones |
| 3:00 PM | 4:00 PM | Both zones |
| 4:00 PM | 5:00 PM | ET only |
| 5:00 PM | 6:00 PM | — |
| 6:00 PM | 7:00 PM | — |
| 7:00 PM | 8:00 PM | — |
| 8:00 PM | 9:00 PM | — |
| 9:00 PM | 10:00 PM | — |
| 10:00 PM | 11:00 PM | — |
| 11:00 PM | 12:00 AM next day | — |
What ET and AST Actually Are
ET — Eastern Time
New York, Toronto, Washington DC, Atlanta, Miami, Boston. Standing at UTC-5:00 as written, and the region does change its clocks, so its live offset moves by an hour twice a year. The next change is on Sunday, November 1, 2026, to EST.
Eastern Time covers roughly half the US population and, because of that, is the zone most American business defaults to when nobody specifies one.
AST — Atlantic Standard Time
Halifax, San Juan, Santo Domingo, Bermuda. Standing at UTC-4:00 as written, and the region does change its clocks, so its live offset moves by an hour twice a year. The next change is on Sunday, November 1, 2026, to AST. AST also stands for Arabia Standard Time (UTC+3), used in Saudi Arabia, Iraq and Kuwait.
Atlantic Standard Time is the only North American zone whose name is more commonly associated, worldwide, with a completely different zone — Arabia Standard Time.
What This Means in Practice
Both sides change clocks, on different dates
Both regions observe daylight saving but do not switch on the same day, so for a week or two each spring and fall the gap between them is an hour different from the rest of the year. Those short windows are where recurring invitations quietly break.
Close enough to share a working day
At only 1 hour apart, the two working days overlap almost completely. Scheduling is barely constrained by the difference.
Major Cities in Each Zone
Cities on ET
Cities on AST
Frequently Asked Questions
What is the time difference between ET and AST?
AST is 1 hour ahead of ET.
What is 9:00 AM ET in AST?
9:00 AM ET is 10:00 AM AST.
What are the best hours to schedule a call between ET and AST?
Between 9:00 AM and 4:00 PM ET, which is 10:00 AM to 5:00 PM AST. Both sides are inside normal business hours through that window.
Does the difference between ET and AST change during the year?
Yes. Both regions observe daylight saving, and they do not switch on the same dates, so the gap shifts by an hour at least twice a year. The next clock change is on Sunday, November 1, 2026.
Does AST always mean Atlantic Standard Time?
AST also stands for Arabia Standard Time (UTC+3), used in Saudi Arabia, Iraq and Kuwait.