That's not entirely correct, actually. Before artificial lightning got introduced, people slept in two phases, and woke up in the middle of the night to do thin

That's not entirely correct, actually. Before artificial lightning got introduced, people slept in two phases, and woke up in the middle of the night to do things. There were even books that suggested things to do in the time before the two sleeps (besides having sex and praying, that is). More here: https://en.wikipedia.org/wiki/Segmented_sleep https://en.wikipedia.org/wiki/Segmented_sleep and I apologize for not finding a better source.