Convertir EST en GMT : heure de l'Est en heure de Greenwich

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Converting US Eastern Time (EST) to Greenwich Mean Time (GMT) is one of the most common scheduling moves for anyone working between the Americas and Europe/Africa. Eastern Time shifts with US daylight saving, so the gap to GMT changes twice a year. Here's the clean version.

Time Zone Overview

Eastern Time (EST/EDT)

US Eastern Time is EST (UTC−5) in winter and EDT (UTC−4) during US daylight saving (second Sunday in March to first Sunday in November).

Greenwich Mean Time (GMT)

GMT is UTC+0 in winter. The UK switches to BST (UTC+1) in summer, so the London reference also moves.

Time Difference

US winter (EST) / UK winter (GMT): GMT is 5 hours ahead of EST.

US summer (EDT) / UK summer (BST): GMT (as BST) is 4 hours ahead of EDT.

Mixed periods (limbo weeks): the gap can be 4 or 5 hours depending on which side has switched.

Conversion Formula

GMT = EST + 5 hours (both winter) / EST + 4 hours (both summer)

Quick Reference Table (EST → GMT/BST)