Convert EST to GMT — Time Difference, DST and Hour Chart
Updated: May 2026
Eastern Standard Time (EST) sits at UTC-5, exactly five hours behind Greenwich Mean Time (UTC+0). That five-hour gap is fixed during winter, but the introduction of US Daylight Saving Time and UK Summer Time means the real offset between the two time zones can vary between four and six hours depending on the calendar date.
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EST and GMT at a glance
EST stands for Eastern Standard Time and is the winter time used by the US East Coast, including New York, Washington DC, Boston, Miami, and Toronto. GMT, or Greenwich Mean Time, is the time at the Royal Observatory in Greenwich, London, and also the reference point for UTC (Coordinated Universal Time) during winter months in the UK.
The fixed offset is straightforward: to convert EST to GMT, add 5 hours. 8:00 AM EST becomes 1:00 PM GMT. Midnight EST (00:00) becomes 5:00 AM GMT. The direction is always the same — London is ahead of New York.
GMT and UTC are not technically identical but the difference (under a second) is irrelevant for scheduling. For practical purposes, treat GMT and UTC+0 as the same when converting times.
EST to GMT quick conversion table
| EST (UTC-5) | GMT (UTC+0) | Note |
|---|---|---|
| 12:00 AM (midnight) | 5:00 AM | — |
| 3:00 AM | 8:00 AM | Early morning NY → morning London |
| 6:00 AM | 11:00 AM | NY opening → London midday |
| 8:00 AM | 1:00 PM | NY work start → London afternoon |
| 9:00 AM | 2:00 PM | NY stand-up → London 14:00 |
| 12:00 PM (noon) | 5:00 PM | NY lunch → London close of business |
| 3:00 PM | 8:00 PM | NY afternoon → London evening |
| 5:00 PM | 10:00 PM | NY end of day → London night |
| 8:00 PM | 1:00 AM (+1 day) | Crosses midnight in London |
| 11:00 PM | 4:00 AM (+1 day) | — |
How DST complicates the EST–GMT gap
The United States and the United Kingdom both observe Daylight Saving Time, but they switch on different dates. This creates three distinct windows during the year where the actual offset between New York and London changes.
- November to mid-March (both on standard time): EST (UTC-5) vs GMT (UTC+0) — 5 hours difference.
- Mid-March to late March (US on EDT, UK still on GMT): EDT (UTC-4) vs GMT (UTC+0) — only 4 hours difference. This window lasts about two weeks.
- Late March to late October (both on summer time): EDT (UTC-4) vs BST (UTC+1) — 5 hours difference again.
- Late October to early November (US still on EDT, UK back on GMT): EDT (UTC-4) vs GMT (UTC+0) — 4 hours difference. Another short transition window.
The two transition windows (roughly two weeks each in spring and autumn) are when scheduling mistakes are most common. Always use a DST-aware converter for dates near the last Sunday of March or the last Sunday of October.
When scheduling a recurring meeting between New York and London, specify the time in UTC or use a calendar tool that stores events in UTC and displays them in each attendee's local time zone. Never hardcode "5 PM EST = 10 PM GMT" as a permanent rule.
Working hours overlap between EST and GMT
Standard business hours are roughly 9 AM to 5 PM local time. The window where both sides are at work simultaneously is narrow and depends on the time of year.
- In winter (5h difference): London works 9 AM–5 PM GMT. New York works 9 AM–5 PM EST (2 PM–10 PM GMT). Overlap: 2 PM–5 PM GMT / 9 AM–12 PM EST. Only 3 hours of shared business time.
- In summer (5h difference again, but EDT/BST): Same 3-hour window but shifted to 2 PM BST–5 PM BST / 9 AM EDT–12 PM EDT.
- During transition weeks (4h difference): A slightly wider 4-hour window becomes available, 1 PM–5 PM London / 9 AM–1 PM New York.
For transatlantic teams, the best meeting slot is 9–11 AM EST (2–4 PM GMT) year-round, giving enough buffer for both sides to avoid very early mornings or late evenings.
Why "EST" is often used incorrectly
Many people write "EST" year-round to mean Eastern Time, even when New York is on EDT (Eastern Daylight Time) during summer. This creates ambiguity in international scheduling. Strictly speaking, EST only applies between the first Sunday of November and the second Sunday of March.
The safest approach is to avoid EST/EDT entirely and write times in UTC or specify the IANA zone name (America/New_York). A calendar invite or API call using America/New_York automatically applies the correct offset for any given date, including DST transitions.
Similarly, GMT is technically a time zone, not an offset name. UTC+0 is the offset. Some tools treat GMT as always UTC+0 even when UK clocks are on BST — this is another source of confusion. When in doubt, use UTC explicitly.
Frequently asked questions
What is the difference between EST and GMT?
EST (Eastern Standard Time) is UTC-5, while GMT is UTC+0. EST is 5 hours behind GMT during winter months. During US DST, Eastern Time becomes EDT (UTC-4), reducing the gap to 4 hours when the UK is still on GMT.
When does the US switch from EST to EDT?
The US switches to EDT (summer time) on the second Sunday of March at 2:00 AM local time. Clocks jump forward to 3:00 AM. It reverts to EST on the first Sunday of November at 2:00 AM (clocks fall back to 1:00 AM).
Does the UK observe GMT year-round?
No. The UK uses GMT only from late October to late March. From late March to late October, the UK observes BST (British Summer Time, UTC+1). This means the gap between New York and London is 4 hours during brief spring/autumn windows and 5 hours most of the year.
What is 9 AM EST in GMT?
9:00 AM EST equals 2:00 PM GMT. Add 5 hours to convert from EST to GMT. If New York is on EDT (summer), 9:00 AM EDT equals 1:00 PM GMT (add 4 hours).
Need to convert a specific date and time? Use the live converter — it handles DST automatically.
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