New York vs London Time: The Complete Business Scheduling Guide

New York and London are separated by 5 hours for most of the year. That sounds simple until you realize it shifts to 4 hours for three weeks in March and again in November, and that your real usable overlap is only about 3 hours. Here's how teams at banks, law firms, and tech companies actually handle it.

The Numbers: New York vs London Time Difference

London is on GMT (UTC+0) in winter and BST (UTC+1) in summer. New York is on EST (UTC-5) in winter and EDT (UTC-4) in summer. The result:

The US and UK switch to daylight saving time on different dates. The US "springs forward" on the second Sunday in March; the UK follows on the last Sunday in March. That creates a 2-3 week window where the gap narrows to 4 hours. The same thing happens in reverse in October/November. If you have a standing 2 PM London / 9 AM New York call, it will break twice a year. Put a calendar reminder a week before each DST switch.

The Real Business Hours Overlap

London's workday: 9 AM – 5:30 PM GMT. New York's workday: 9 AM – 5 PM ET. The overlap is 2 PM – 5:30 PM London / 9 AM – 12:30 PM New York. That's roughly 3.5 hours.

In practice, most teams report an effective overlap of about 3 hours once you account for lunch on the London side. Here's what that looks like hour by hour:

The golden slot is 2-3 PM London / 9-10 AM New York. This is when both sides are at their sharpest. If you only have one recurring meeting per week, put it here.

The DST Trap (and How to Avoid It)

Every March and October, teams with US-UK meetings face the same chaos: someone shows up an hour early or misses the call entirely.

The fix is straightforward:

• Always schedule in one timezone and let calendar apps convert. If you say "let's meet at 2 PM London," everyone's calendar handles the math. If you say "let's meet at 9 AM New York," same thing. Never say "let's meet at 2 PM London / 9 AM New York" — that statement becomes wrong twice a year.
• Use a tool that handles DST automatically. WorldClock.lol's meeting planner uses the IANA timezone database and always shows the correct converted time, including during DST transitions.
• Set a calendar alert for DST switch weeks. US clocks change on the 2nd Sunday in March and 1st Sunday in November. UK clocks change on the last Sunday in March and October.

Common Meeting Scenarios

Morning standup (engineering teams)

Most US-UK engineering teams land on 2:30 PM London / 9:30 AM New York. Early enough that London hasn't checked out, late enough that New York has had coffee. If you have a third timezone (e.g., San Francisco at 6:30 AM), consider rotating the standup time weekly or doing async standups for the West Coast.

Client presentations

Client-facing meetings work best at 3 PM London / 10 AM New York. It's a "normal" time in both cities and avoids the impression that either side is going out of their way.

All-hands / town halls

For company-wide meetings, 4 PM London / 11 AM New York tends to work — it's a natural pre-lunch slot for New York and late enough in London that European offices can join. If you also have APAC team members, you'll need to rotate or record.

Quick conversion reference

For Financial Services: Market Hours

The London Stock Exchange opens at 8 AM GMT and closes at 4:30 PM GMT. The NYSE opens at 9:30 AM ET and closes at 4 PM ET. The overlap when both markets are open is 9:30 AM – 11:30 AM ET / 2:30 PM – 4:30 PM GMT — just 2 hours. This is the busiest period for cross-Atlantic trading desks and the worst time to schedule non-urgent meetings.

Making the Gap Work: Async Patterns

3 hours of overlap isn't much. Teams that do this well don't try to cram everything into the overlap window. Instead:

• London starts the day by reviewing New York's end-of-day output. PRs submitted at 5 PM ET get reviewed at 9 AM GMT.
• New York starts the day by reviewing London's output. The reverse handoff happens naturally.
• Reserve the overlap for decisions, not updates. Use the 3-hour window for meetings that require real-time discussion. Everything else goes in Slack, email, or a shared doc.
• Record every meeting. Not everyone can make the overlap window every time. Recordings let people catch up async.