[opportune]

One more independent variable you might want to test: when you go to bed. I've found that the earlier I go to bed, the higher quality sleep (I'm sure there is a point at which I would begin getting worse sleep, but I haven't reached it). I've tried anywhere from 9PM to 3AM. 9PM is a little too early to do if you aren't trying to "catch up" on sleep but I've been getting great results going to sleep at 10PM every night. I usually fall asleep around 10:30 or 11PM and wake up naturally to the sun around 7-8AM.

Never feel tired at work anymore, but I do actually start getting tired around 8-9PM when the caffeine from work starts wearing off. The energy and focus is great

[matwood]

Agreed. I get up every morning around 6am. Some mornings I get up at 5am for a group workout thing, but it's mostly around 6am. I'm normally in bed right before 10 because I have found out through experience that I need ~7-8 hours of sleep/night.

I can shift this a bit, say go to bed around 11 or 12 and sleep later, but I am not nearly as productive in the mornings then. If I push this more extreme and say go to bed at 2-3am, even if I sleep until 10 or 11, I am wrecked the next day. I actually feel worse than if I only got 6 hours of sleep instead, but went to bed earlier.