Both mean “Eastern Time” in the US — but they are one hour apart, and using the wrong one breaks meeting schedules twice a year.
| EST | EDT | |
|---|---|---|
| Full name | Eastern Standard Time | Eastern Daylight Time |
| UTC offset | UTC-5 | UTC-4 |
| When | Nov – Mar (winter) | Mar – Nov (summer) |
| Offset to India (IST) | +10:30 | +9:30 |
In everyday speech, Americans say “EST” year-round, even in July when the clocks are actually on EDT. Calendar tools mostly save you by using “Eastern Time” (ET), which switches automatically. The trouble starts when someone types a fixed offset — “2 PM EST” in June is ambiguous: do they mean 2 PM on the East Coast (really EDT), or literal UTC-5, which would be 3 PM local?
Rule of thumb: if someone on the US East Coast says EST in summer, they almost always mean local Eastern Time (EDT). Confirm with a city — “2 PM New York time” is unambiguous.
US daylight saving runs from the second Sunday of March (clocks jump forward at 2 AM) to the first Sunday of November (clocks fall back). That's nearly 8 months of EDT — daylight time is the majority state.
India doesn’t observe DST, so the India gap changes twice a year: +10:30 during EST, +9:30 during EDT. A recurring 8 AM Eastern call lands at 6:30 PM IST in winter but 5:30 PM IST in summer. Our EST to IST converter handles the current offset automatically, and the DST guide lists the exact change dates.
The US East Coast uses EDT (UTC-4) from the second Sunday of March through the first Sunday of November, and EST (UTC-5) the rest of the year. In summer, it is EDT.
Yes — EST by definition is UTC-5. But the East Coast only uses EST in winter; in summer local time is EDT (UTC-4).
ET (Eastern Time) refers to the local clock in the Eastern zone, which is EST in winter and EDT in summer. EST is only the winter half.