How many hours behind GMT is EST?

Eastern Standard Time (EST, UTC−5) is 5 hours behind GMT (UTC+0) during winter. In summer, when the US East Coast shifts to EDT (UTC−4) and the UK shifts to BST (UTC+1), New York is still 5 hours behind London. However, during the brief transition windows in March and October when only one side has changed clocks, the gap can be 4 or 6 hours.

When is the EST/GMT gap only 4 hours?

The gap narrows to 4 hours during the brief window in mid-March when the US has sprung forward to EDT (UTC−4) but the UK has not yet switched to BST (still GMT, UTC+0). Similarly, in late October after the UK falls back to GMT but before the US falls back to EST, the gap temporarily becomes 4 hours again.

What is the best time for a call between New York and London?

The practical overlap window is 2–5 PM London time (9 AM–12 PM New York time) in winter, or 2–5 PM BST (9 AM–12 PM EDT) in summer. This lets New York join during morning hours while London is in the early-to-mid afternoon. Avoid scheduling after 5 PM London time (noon New York), as London is at end-of-day.

EST vs GMT: Time Difference and Conversion

February 14, 2026

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Frequently Asked Questions

How many hours behind GMT is EST?: Eastern Standard Time (EST, UTC−5) is 5 hours behind GMT (UTC+0) during winter. In summer, when the US East Coast shifts to EDT (UTC−4) and the UK shifts to BST (UTC+1), New York is still 5 hours behind London. However, during the brief transition windows in March and October when only one side has changed clocks, the gap can be 4 or 6 hours.
When is the EST/GMT gap only 4 hours?: The gap narrows to 4 hours during the brief window in mid-March when the US has sprung forward to EDT (UTC−4) but the UK has not yet switched to BST (still GMT, UTC+0). Similarly, in late October after the UK falls back to GMT but before the US falls back to EST, the gap temporarily becomes 4 hours again.
What is the best time for a call between New York and London?: The practical overlap window is 2–5 PM London time (9 AM–12 PM New York time) in winter, or 2–5 PM BST (9 AM–12 PM EDT) in summer. This lets New York join during morning hours while London is in the early-to-mid afternoon. Avoid scheduling after 5 PM London time (noon New York), as London is at end-of-day.