This year the clocks go forward to British Summer Time on Sunday 30th March, and back to GMT on October 26th – put those in your diary now. (Or your Outlook Calendar at least – if you have a diary, they probably come printed in already.)

I’ve been perusing some information about the system for deciding when the clocks change on the Department for Business Enterprise & Regulatory Reform website (as you do). Nowadays, it’s always the last Sunday in March and the last in October. It’s the same in all European Union member states and has been set down via EC Directive since way back when (i.e, 1981).

Directive 2000/84/EC of the European Parliament and of the Council of 19 January 2001 on summer-time arrangements sayeth in particular:

(2) Given that the Member States apply summer-time arrangements, it is important for the functioning of the internal market that a common date and time for the beginning and end of the summer-time period be fixed throughout the Community.

(3) Since the summer-time period considered most appropriate by the Member States runs from the end of March to the end of October, it is appropriate that that period therefore be maintained.

As directives have to be implemented into British law to take effect, this is done through Orders in Council under the European Communities Act 1972. The 1972 Summer Time Act (it was all go in 1972) is amended by the Order to enact the change.

The current arrangement settling on the last Sundays in March and October was introduced via the 9th Directive, which came into force through the Summer Time Order 2002. The main effect, as we already used roughly the same system, was to remove the previous contingency the moved the switch to BST earlier by a week if it would have fallen on Easter Sunday. I note that in the original 1972 arrangements, the changes happened at 2am GMT – now they happen at 1am.

Here endeth the lesson.