He sleeps during the day because Bruce Wayne is a notorious playboy.
“Crime doesn’t sleep, so neither do I.” ~Batman hallucinating a conversation with the Joker due to sleep deprivation
Turns out the city doesn’t have flamboyantly dressed supervillains at all. Batman is just running around Gotham, sleep deprived as hell, grabbing confused commuters by the shoulders and accusing them of being The Penguin.
My friend tried this thing where you nap for 20 minutes every 4 hours or so.
They managed to get into a good rhythm with it for a while.
They stopped because they missed sleep and it was weird as fuck being awake all the time.
They had an amazing ability to fall asleep almost instantly so I imagine that made it much easier.
It’s called the Everyman/uberman sleep cycle depending on how extreme you go and it’s pretty interesting. Tried the Everyman for awhile and it was nice but if you get sick or otherwise mess it up it you basically have to restart the whole process. Also tough to do if you’re not single, once I met my wife I fully gave it up.