Atlantic Standard Time is 4 hours behind London.

Frequently asked

Quick answers about converting between Atlantic Standard Time and London. Can't find what you need? Email [email protected].

What is the time difference between Atlantic Standard Time and London?

Atlantic Standard Time is 4 hours behind London right now. We always show the live, daylight-saving-correct difference, so this figure already accounts for whichever side is observing summer time today.

When it's 9am in Atlantic Standard Time, what time is it in London?

9am in Atlantic Standard Time is 1pm in London. Use the hour-by-hour table above to read any other time across — find the row and read the matching cell in the other column.

What's the best time for a call between Atlantic Standard Time and London?

9am–1pm in Atlantic Standard Time lines up with 1pm–5pm in London — both sides are inside a 9-to-5 working day.

Does this account for daylight saving time?

Yes. We track every clock change in both places, so the abbreviations you see — ADT and BST — are the ones actually in effect right now, not a fixed all-year value. When either side changes its clocks, this page updates automatically.

Why is the date sometimes different on each side?

When two places are far enough apart, the same moment can fall on different calendar days. That is why some conversions are marked "previous day" or "next day" — it is the same instant in time, read off two clocks that crossed midnight at different points.