10am in Chatham Standard Time is 10:15pm in British Summer Time on the previous day.

Frequently asked

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

What is the time difference between Chatham Standard Time and British Summer Time?

Chatham Standard Time is 11 hours 45 minutes ahead of British Summer Time 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 10am in Chatham Standard Time, what time is it in British Summer Time?

10am in Chatham Standard Time is 10:15pm in British Summer Time on the previous day. It lands deep outside working hours in British Summer Time — see the best time to meet below for a friendlier slot. Use the hour-by-hour table above to read any other time across.

What's the best time for a call between Chatham Standard Time and British Summer Time?

There's no comfortable 9-to-5 overlap between Chatham Standard Time and British Summer Time — they sit on opposite sides of the planet's working day. Plan for an early or late call on one side, or hand work off asynchronously.

Does this account for daylight saving time?

Yes. We track every clock change in both places, so the abbreviations you see — +12:45 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.