EST vs EDT — cities and working rhythm
US East Coast — the reference clock for US business, Wall Street, US law and consulting firms, most Fortune 500 HQ. Business hours 9 AM – 6 PM ET. Note: EST is the winter offset (UTC-5); EDT (UTC-4) is the summer offset — "ET" is the year-round non-committal way to refer to this zone in scheduling apps.
US East Coast summer offset (mid-March to early November), UTC-4. The narrower gap to Europe (only 4 h during northern-hemisphere summer) means early-morning EU meetings align with reasonable East Coast times.
Time gap: EDT is 1.0 hours ahead of EST (standard-time offsets — daylight-saving flips shift this by an hour twice a year in most northern-hemisphere zones).