What is the time difference between London and Hanoi?

Hanoi (ICT, UTC+7) is 7 hours ahead of London in winter (GMT, UTC+0) and 6 hours ahead in summer when the UK observes BST (UTC+1). The tool always shows the live offset for today.

Does the tool account for UK Daylight Saving Time?

Yes. The calculation uses the IANA timezone "Europe/London", which automatically switches between GMT and BST. Hanoi does not observe DST, so the gap changes by one hour each spring and autumn.

When does the UK change its clocks?

The UK moves to BST (UTC+1) on the last Sunday in March and returns to GMT (UTC+0) on the last Sunday in October. During BST the London–Hanoi gap is 6 hours; during GMT it is 7 hours.

What are the overlapping business hours between London and Hanoi?

During GMT (winter): 09:00–11:00 London = 16:00–18:00 Hanoi — a 2-hour window. During BST (summer): 09:00–12:00 London = 15:00–18:00 Hanoi — a 3-hour window. The planner grid shows the exact overlap for today.

Can I convert a specific time from London to Hanoi?

Yes. Use the custom time converter at the bottom of the tool: enter any London hour and the equivalent Hanoi time is shown instantly.

Time Difference: London to Hanoi

See the live time gap between London and Hanoi and find the best hours for cross-timezone meetings.

London

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GMT/BST

Hanoi

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ICT (UTC+7)

Current offset

Hanoi is … ahead of London

24-Hour Meeting Planner

Each column is one hour. Green = both cities in business hours (09:00–18:00). Blue = London only. Orange = Hanoi only. Gray = outside business hours.

Overlap (both in office) London office Hanoi office Outside office

Convert a Specific Time

London time:

= Hanoi time: --:00

Summary

London operates on GMT (UTC+0) in winter and BST (UTC+1) in summer, while Hanoi is always on ICT (UTC+7). The gap is therefore 7 hours in winter and 6 hours in summer. This tool shows live clocks for both cities and a 24-hour grid that highlights overlapping business hours so teams can schedule meetings without mental arithmetic.

How it works

The tool reads your browser clock and calculates the current local time in both London and Hanoi using their IANA timezone identifiers.
London observes GMT (UTC+0) in winter and BST (UTC+1) in summer; Hanoi is always ICT (UTC+7).
The offset shown is the difference between the two cities at the current moment, automatically adjusting for UK Daylight Saving Time.
The 24-hour meeting planner highlights London business hours (09:00–18:00) and Hanoi business hours (09:00–18:00) on the same grid.
Overlapping working hours are shown in green so you can instantly identify the best times to schedule calls.

Use cases

Schedule video calls between a London office and a Hanoi team.
Confirm whether a Hanoi colleague is still at work when it is mid-afternoon in London.
Quickly check what time it is in Hanoi before sending a message.
Plan client meetings that work for both UK and Vietnam participants.
Understand the BST vs GMT shift and how it affects the London–Hanoi gap.
Convert a specific London time to the equivalent Hanoi time.

Frequently Asked Questions

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