I am a huge stickler for time-zone acumen! I'm glad to hear I'm not the only one.

US time is relatively easy - it gets a bit tricky in the UK because most people don't realise that the UK is on GMT only when daylight-saving time is not in effect (this is because GMT, or more correctly UTC, never changes); during the summer, the British Isles are on BST (British Summer Time).

However, on the continent, the time zone is CET all year round even though it changes for daylight-saving time as well.

Let's not even get started on Australia and New Zealand.