Convert BST (British Summer Time) to AEDT (Australian Eastern Daylight Time)

Which BST is this?

BST names more than one zone. This page reads it as British Summer Time at UTC+1, which is the reading most converters take. There is one other: Bangladesh Standard Time at UTC+6, used in Bangladesh, all year.

The letters on a meeting invitation do not say which one is meant. If yours is not British Summer Time, the answer above is wrong, and not by a little:

Any converter has to pick one of these readings before it can answer, and two of them can pick differently — a page of search results for a BST conversion can show you both answers with neither being wrong. The one to trust is whichever states the zone it means rather than only the letters. Where it matters, ask which country the sender is in.

Best time to schedule a meeting

Standard 9–5 working hours do not overlap at all between BST and AEDT. Someone has to take an early or late call — or use asynchronous communication instead.

BST to AEDT conversion table

About BST

British Summer Time (BST) is UTC+1. It is used in the UK from late March to late October.

British Summer Time is UTC+1, in force in the UK and Ireland from the last Sunday in March to the last Sunday in October. The abbreviation is ambiguous: BST also means Bangladesh Standard Time, UTC+6, five hours away. Within the UK it is the reason "GMT" is wrong for most of the year — the clocks are on BST from spring to autumn, and only the winter half of the year is actually GMT.

About AEDT

Australian Eastern Daylight Time (AEDT) is UTC+11. It is used in Sydney and Melbourne from October to April.

Australian Eastern Daylight Time is UTC+11, the summer clock for Sydney, Melbourne and Canberra — and summer here means October to April, the opposite half of the year from the northern hemisphere. That inversion is what makes Australia–Europe scheduling awkward: for a few weeks each spring and autumn the two regions are shifting in opposite directions, and the offset between them changes twice within a month.

Does this gap change with the seasons?

This gap is seasonal. The abbreviations themselves are fixed offsets, but the region on BST switches to GMT (UTC+0) from late October to late March, and the region on AEDT switches to AEST (UTC+10) from April to October. So the 10-hour figure on this page is correct for the part of the year when both places are actually on these abbreviations, and changes by an hour outside it.

Because both sides shift, there are also short windows each spring and autumn when one has changed and the other has not — the two regions do not switch on the same date. A recurring meeting set during one of those windows is an hour out for a week or two, which is the most common way this catches people.

This is the reason scheduling systems store an IANA zone such as Region/City rather than an offset or an abbreviation: the zone knows its own rules and the offset does not.

Frequently asked questions