The Sunday Night Reset

Sunday night is, reliably, the worst night of most people's week. The usual explanation is dread about Monday.

That's part of it. The larger part is arithmetic.

What actually happened

If you sleep 11pm to 7am on weeknights and 1am to 10am at the weekend, you've moved your body clock roughly three hours later in two nights. On Sunday you get into bed at eleven and ask a system that is now running on a 2am schedule to fall asleep on command.

It won't. Then you lie there doing the arithmetic — six hours if I sleep now, five and a half if I don't — which is the most reliable way to guarantee neither.

The chronobiologist Till Roenneberg named this social jet lag. You flew three time zones west on Friday and back east on Monday morning. Nobody gave you a holiday for it.

What we do instead

Saturday's lie-in is capped at an hour. This is the whole trick and it's unpopular. Not up at seven on a Saturday — but not eleven either. An hour of drift, then the same wake time as always.

Sunday morning gets light early. Outside before ten if we can manage it. Morning light pulls the clock earlier, which is exactly the correction needed after two later nights.

Sunday evening starts earlier than usual. Lights down at nine rather than half past. Not to fall asleep earlier by force, but to give the system a longer run-up.

Tomorrow gets dealt with before eight. Ten minutes, written down, done. Everything that would otherwise arrive at midnight gets an earlier appointment.

Sunday night isn't a mood problem. It's a timing problem wearing a mood's clothes.

And if it's already eleven and you're wide awake

Don't lie there. Get up, low light, something dull, back when sleepy. And don't calculate the hours — turn the clock around.

One short Sunday is survivable. It's the fortnight of catching up that follows that does the damage.