What is the normal time difference between London and Boston?

London is usually 5 hours ahead of Boston. London observes GMT (UTC+0) in winter and BST (UTC+1) in summer; Boston observes EST (UTC-5) in winter and EDT (UTC-4) in summer. Both cities shift clocks in spring and autumn, keeping the gap at 5 hours for most of the year.

When is the time difference only 4 hours?

There are two brief windows each year when the US and UK change their clocks on different weekends. During those windows the gap shrinks to 4 hours. This tool shows the real offset live so you always have the correct number.

What time zone does Boston use?

Boston uses the America/New_York IANA timezone — Eastern Standard Time (EST, UTC-5) in winter and Eastern Daylight Time (EDT, UTC-4) in summer. Boston is in the same timezone as New York City.

When does the UK change its clocks?

The UK moves clocks forward on the last Sunday in March at 01:00 GMT (becoming BST, UTC+1) and back on the last Sunday in October at 02:00 BST (returning to GMT, UTC+0).

When does Boston (US East Coast) change its clocks?

The US shifts clocks forward on the second Sunday in March at 02:00 EST (becoming EDT, UTC-4) and back on the first Sunday in November at 02:00 EDT (returning to EST, UTC-5).

What are good meeting times for both London and Boston?

The best overlap is 14:00–18:00 London time (09:00–13:00 Boston time during the standard 5-hour offset). The meeting overlap table on this page highlights those windows automatically.

Time Difference: London to Boston

See the current time in London and Boston side by side, with the exact hour offset and a time converter, updated live every second.

London, United Kingdom

--:--:--

GMT UTC+0

Boston, Massachusetts

--:--:--

EST UTC-5

Current Offset

+5 hours

London is 5 hours ahead of Boston

Convert a Specific Time

Enter a time in one city to see the equivalent in the other.

London time

Boston time

Edit either field — the other updates instantly based on the current offset.

Meeting Overlap Finder

Business hours (09:00–18:00) highlighted — best overlap shaded

London	Boston	Status

London to Boston Time Reference

Based on the current offset — updates automatically

London	Boston

Summary

This tool displays the live current time in both London (Europe/London — GMT in winter, BST in summer) and Boston, Massachusetts (America/New_York — EST in winter, EDT in summer) side by side. The exact offset is calculated automatically and adjusts whenever either city transitions for Daylight Saving Time. Use it to schedule transatlantic calls, coordinate remote teams, or check whether a colleague in Boston is still at work.

How it works

Your browser reads the current moment from your device clock.
It converts that moment to Europe/London time using the IANA timezone database built into modern browsers.
The same moment is converted to America/New_York time, which Boston observes.
The UTC offsets of both cities are compared to calculate the exact hour difference.
All three values — London time, Boston time, and the offset — refresh every second.
DST transitions for both cities are handled automatically, so the offset switches correctly each spring and autumn.

Use cases

Scheduling video calls between London and Boston offices.
Checking if a colleague in Boston is still at their desk.
Planning transatlantic travel and arrival time comparisons.
Remote teams coordinating daily standups across the UK and US East Coast.
Finding overlapping business hours for London-Boston meetings.
Verifying whether both cities currently observe daylight saving time.
Students at Boston universities arranging online sessions with UK institutions.
Checking live broadcast times for events in either city.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu