I find myself naturally going to bed early (often 8 or 9pm), awake for one or two hours around 1 or 2pm, and then waking up early (5-6am). It feels very natural and comfortable. And after I noticed this pattern for myself, I realized it may have been a very common sleep pattern for some of our ancestors. It’s often called segmented or biphasic sleep.
In my early twenties, I did experiment with sleeping four times one hour daily, and it worked very well – apart from socially, and that’s why I didn’t continue. I found myself needing my hour of sleep, but couldn’t or wouldn’t for work or social reasons. This is called polyphasic sleep.