How many hours ahead is London compared to Seattle?

London is typically 8 hours ahead of Seattle in winter (GMT vs PST) and 9 hours ahead during the brief period each spring and autumn when the two regions switch DST on different dates. In summer, both are on DST so the gap returns to 8 hours (BST vs PDT).

When do the time zones change?

The UK moves to BST on the last Sunday of March and back to GMT on the last Sunday of October. The US moves to PDT on the second Sunday of March and back to PST on the first Sunday of November. During the brief windows when one region has changed and the other has not, the offset is 9 hours.

What are good overlap hours for a London–Seattle meeting?

In standard time (winter), 5–6 PM London (GMT) equals 9–10 AM Seattle (PST) — a practical overlap window. In summer, the gap remains 8 hours (BST vs PDT), so 4–5 PM London equals 8–9 AM Seattle.

Does this tool account for daylight saving time?

Yes. The offset is computed live using the JavaScript Intl API, which applies the correct DST rules for both the Europe/London and America/Los_Angeles time zones at any given moment.

Is Seattle the same time zone as Los Angeles?

Yes. Both cities use the America/Los_Angeles IANA zone (PST/PDT), so the London–Seattle offset equals the London–Los Angeles offset.

Time Difference London to Seattle

Name: Time Difference London to Seattle
Availability: InStock
Author: Nham Vu

See the live time gap between London and Seattle and convert any time to schedule meetings across both cities.

London

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GMT

Seattle

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PST

Current offset: – London is ahead of Seattle

Meeting Time Converter

Enter London time

Enter Seattle time

Business Hours Overlap

Standard working hours: 9 AM – 5 PM local time.

Summary

See the live time gap between London and Seattle and convert any time to schedule meetings across both cities.

How it works

The tool reads your browser clock and calculates the current local time in both London and Seattle.
London follows GMT (UTC+0) in winter and BST (UTC+1) in summer (last Sunday of March to last Sunday of October).
Seattle follows PST (UTC-8) in winter and PDT (UTC-7) in summer (second Sunday of March to first Sunday of November).
The offset shown is the difference between the two zones at this exact moment.
Use the converter to enter any hour in either city and instantly see the corresponding time in the other.

Use cases

Schedule a video call between a London office and a Seattle team.
Find out whether a Seattle colleague is likely awake before sending a message.
Plan a product launch time that works in both cities.
Convert a London broadcast start time to Seattle local time.
Check whether UK business hours overlap with US Pacific working hours.

Frequently Asked Questions

Last updated: 2026-06-09 · Reviewed by Nham Vu