Without the bluish light keeping me stimulated and awake I get tired more quickly. Once I'm tired enough, I just go to sleep.

I've noticed that I can't make it to 4 AM anymore, but I'd just attributed it to getting older. Perhaps it is f.lux's doing after all.

f.lux is an awesome little thing I had installed for months. Then on the excitement of moving to a new place, I removed it. And I could stay awake thru the night again. So it wasn't old age after all. Now I will put it back again.

I use f.lux and think it's great. I recently started taking a small amount (~1.5mg) of melatonin after reading a post[0] by Gwern and the accompanying discussion on HN[1]. I find that taking it ~30 minutes before I want to go to bed makes it much, much easier to "tear myself away" from the computer, book, etc. and go to bed.

0. http://www.gwern.net/Melatonin 1. https://news.ycombinator.com/item?id=6495358

Bright blue light disturbs your natural sleepishness feeling (melatonin/etc), so the need to sleep is felt as, say, exhaustion which is different and comes later.