The eight p.m. stop

Three boundaries hold my sleep together. They are small and unfashionable and they were each, when I instituted them, slightly painful to start. They have, after years of practice, become the architecture that the rest of my evening builds itself around.

The caffeine stop at twelve

Caffeine has a half-life of about five to six hours. The coffee I drink at eight in the morning is, in the body, mostly cleared by the evening. The coffee I drink at one in the afternoon is, when I lie down at eleven, still present at perhaps twenty-five percent of its original concentration in my system. This is enough to fragment the early hours of sleep in a way that I cannot consciously feel but that my morning self can.

I now stop caffeine at noon. This was, for the first month, the most painful of the three boundaries to establish. The afternoon energy slump felt real and unavoidable. I have, over time, learned to ride the slump with a short walk or a cup of warm water with lemon, and the slump has gradually become less pronounced as my sleep has improved.

The food stop at eight

Digestion takes work. Work that happens after eight is work that the body is doing instead of the recovery work it should be doing in the early hours of sleep. The body can, of course, do both, but the sleep is shallower and the morning is, in measurable ways, less rested.

I stop eating at eight. If I am hungry later — and sometimes I am — I have a small cup of warm milk or a piece of fruit, which is light enough not to disrupt the sleep meaningfully. Most evenings I am not hungry by ten and the body has cleared the dinner before I lie down.

The screen stop at ten

Blue light suppresses melatonin. The phone I scroll for thirty minutes at ten-thirty is delaying the onset of my sleep by, in the studies I have read, anywhere from twenty to forty minutes. The delay does not feel like much in the moment. The cumulative effect over a week is significant.

I stop screens at ten. The phone goes into the small tray by the front door. The laptop is closed. The forty-five minutes between ten and ten-forty-five are reading time, in the green chair, with the lamp on. The reading is slower than the scrolling. The slower it gets, the closer to sleep I am.

What the three together do

Sleep that arrives quickly, lasts the full eight hours, and produces a morning I can recognise as rested. The boundaries cost me, in total, perhaps an hour and a half of evening activity per day. The boundaries return, in total, perhaps two and a half hours of better-functioning daytime activity. The exchange is, by every measure I trust, the most favourable trade I have ever made with my own time.