EST to AST: What’s the Difference and When Does It Change?
At 09:00 in New York on 15 January, it’s 10:00 in San Juan. Atlantic Standard Time sits one hour ahead of Eastern Standard Time, every day, all year long, but only when New York is actually on EST. Right now, New York isn’t.
Is EST the same as AST right now?
No. And yes. The answer depends entirely on the date.
AST is fixed at UTC−4. Puerto Rico, which runs on AST, doesn’t touch its clocks in 2026 or 2027. No daylight saving, no spring forward, no fall back. EST is fixed at UTC−5, but New York only uses it for part of the year. Right now New York is on Eastern Daylight Time (EDT), which is UTC−4, the same offset as AST. So today, New York and Puerto Rico show the same local time. That is not because EST equals AST. It’s because EDT and AST happen to share an offset.
From 1 January to 7 March 2026, AST is 1 hour ahead of EST. On 8 March 2026, New York springs forward to EDT and the gap vanishes. It stays gone until 1 November 2026, when New York falls back to EST and the 1-hour difference returns through 31 December. In 2027, the gap runs 1 January to 13 March, disappears until 6 November, then returns through year-end.
How to schedule calls between EST and AST
Book by the numbers, not the label.
When the 1-hour gap is in effect, a 09:00 to 17:00 working day in San Juan overlaps with 09:00 to 16:00 in New York. That’s a 7-hour window. When the zones match, you get the full 8 hours, 09:00 to 17:00 Eastern.
Before you send the invite, check the date against the change dates above. The most common error is using “EST” as a year-round label. It isn’t. If you write “2 PM EST” in July, you’re naming a zone that isn’t in use, and someone will show up an hour late. Write “ET” or “Eastern Time” when you mean the current local time in New York. Write “EST” only when you specifically mean standard time, November to March.
When does the EST to AST gap change in 2026?
The next shift: Sunday, 8 March 2026 at 02:00 local time.
At that moment, New York moves from EST (UTC−5) to EDT (UTC−4). AST and Eastern Time become identical. The 1-hour difference disappears.
It returns on Sunday, 1 November 2026 at 02:00 local time, when New York falls back to EST. Set your calendar for both dates. If you’re scheduling across the Atlantic in summer, treat the zones as the same. Come November, add the hour back. It’s the difference between catching someone at 09:00 and 10:00.
What time is 2 PM EST in AST?
3 PM AST. Add one hour.
If you’re actually in EDT when you ask, the times are identical. Check the date before you convert. From 8 March to 31 October 2026, 2 PM in New York is 2 PM in San Juan.
Does Puerto Rico observe daylight saving time?
No. Puerto Rico stays on Atlantic Standard Time (UTC−4) year-round. It does not change clocks in 2026 or 2027.
Why doesn’t AST change when EST does?
AST belongs to regions like Puerto Rico that chose not to observe daylight saving time. Eastern Time follows the US federal schedule, moving clocks in March and November. That policy difference is the entire reason the gap appears and disappears. The Sunshine Protection Act, which would make DST permanent in the US, passed the Senate in 2022 but stalled in the House. If enacted, Eastern Time would sit at UTC−4 year-round, matching AST permanently. As of now, it hasn’t passed. Check the current Congress for the latest status.
Is AST the same as EDT?
In practice, yes. Both are UTC−4, so local times match during Eastern Daylight Time. The difference: AST is permanent. EDT runs only from March to November.
When is the gap between EST and AST largest?
It’s always exactly one hour when it exists. There’s no wider or narrower window. It’s either 1 hour ahead in winter or 0 hours in summer. The only variable is which months you’re in.