I feel if this ancient Chinese wisdom were accurate, you could substantiate it with some kind of study, and the "Ancient Chinese wisdom" part would be merely an amusing anecdote relevant to the data.
The article is about how little study has been done about sleep:
> One of the biggest problems I’ve discovered is that sleep is such an over talked topic. We get the general idea that we know all about it: how much we need of it, how it impacts us and why this or that happens when we sleep. Once I took a step back to really think about where our knowledge about sleep comes from, I realized that nearly all of it is based on hear-say or what my mom told me when I was in elementary school.
I was merely quoting some well-known wisdom (among Chinese) (but not well-followed) from an old book [1] written based on actual clinical experiences. And it also happens to support fakeer's suggestion. If that's not up to some scientific standards, at least it is one step above "hear-say" and "what my mom told me", don't you think?
This is such a complicated subject, and I doubt there has been any concrete study that can conclusively prove anything. For me, the point of the article is to provoke exactly this kind of discussion.
- falling asleep during the slice from 9pm to 11pm
- remaining sound asleep during the slices from 11pm to 1pm and from 1am to 3am
- waking up during the slice from 3am to 5am