[tarequeh]

Sounds like the OP is happy with his schedule, which is great. However everyone needs different lengths of sleep for the body to process/release toxins. For me it's 8 hours at least to wake up feeling refreshed and not relying on coffee or other stimulants to go through the day. As for waking up feeling tired no matter when, the optimal timing for waking up matters and is at the end of a 90 minute sleep cycle (you need a few of those per night). https://en.wikipedia.org/wiki/Sleep. You can also use iOS apps like "Sleep Cycle" to aid you in waking up at the right time - really made a difference for me. Waking up to a screaming alarm is probably the last thing you want.

[jacalata]

Sounded good except for 'toxins' which I pretty much always see used as a pseudo science catch all. Do you have some cites for that being an actual process?

[scott_s]

Yes, the word "toxins" has been almost completely co-opted by pseudo-science. But the poster may have been referring to a recent study which theorizes that one of the functions of sleep is to remove waste-products ("toxins") from the brain. HN discussion here: https://news.ycombinator.com/item?id=6567966