What is 8 hours of sleep exactly?

I love my sleep, and I need it too. I can’t get way with much less for more than a couple of days before I’m rotten company. The thing is, though, how do you count 8 hours’ sleep?

I go for 8 hours a night if I can, mainly because that’s the received medical wisdom and also because I can’t get the things done I need to get done during the week if there’s less than 16 waking hours left. I sleep more on non-busy weekends, partly to catch up if I’m in debit, and partly because I would sleep more if I could.

But I count my sleep from the moment I close my eyes, until the moment the alarm goes off. It doesn’t matter if it takes me a bunch of minutes to fall asleep – unusual – or if I wake up before my alarm – also unusual unless I’ve something important to wake up for and then the body clock helps out. If my eyes are closed, or I’m dozing, that’s rest and therefore good enough for me.

Perhaps it’s impossible to know how long you’re sleeping, unless you have a partner who spends a month measuring the exact time it takes you to fall asleep so that you can compute an average time to factor into your calculations of ‘true’ sleeping time. This also assumes you don’t have moments – or hours if you suffer this way – of wakefulness in between.

So for me, I keep it simple. From eyes closed til getting out of bed is the sleep I get, no more, no less. A third of the day recovering and filling the tank for the best two-thirds I can manage.