BBC: For millennia, people slept in two shifts—once in the evening, and once in the morning. But why?
From as early as 21:00 to 23:00, those fortunate enough to afford them would begin flopping onto mattresses stuffed with straw or rags – alternatively it might have contained feathers, if they were wealthy – ready to sleep for a couple of hours. (At the bottom of the social ladder, people would have to make do with nestling down on a scattering of heather or, worse, a bare earth floor – possibly even without a blanket.)
A couple of hours later, people would begin rousing from this initial slumber. The night-time wakefulness usually lasted from around 11:00 to about 01:00, depending on what time they went to bed. It was not generally caused by noise or other disturbances in the night – and neither was it initiated by any kind of alarm (these were only invented in 1787, by an American man who – somewhat ironically – needed to wake up on time to sell clocks). Instead, the waking happened entirely naturally, just as it does in the morning.
The period of wakefulness that followed was known as “the watch” – and it was a surprisingly useful window in which to get things done. “[The records] describe how people did just about anything and everything after they awakened from their first sleep,” says Ekirch. Under the weak glow of the Moon, stars, and oil lamps or “rush lights” – a kind of candle for ordinary households, made from the waxed stems of rushes – people would tend to ordinary tasks, such as adding wood to the fire, taking remedies, or going to urinate (often into the fire itself).
For peasants, waking up meant getting back down to more serious work – whether this involved venturing out to check on farm animals or carrying out household chores, such as patching cloth, combing wool or peeling the rushes to be burned.