I suffer from this. I can rise around 6am, but around 2 or 3pm I crash hard. Staying the full day at work becomes a serious chore. I suspect this is because I haven't settled into a proper routine of doing this for more than a week straight. Unfortunately, when I've attempted this, I get incredibly unproductive in the afternoons, then I just feel like crashing when I get home, so in general my quality of life goes significantly down. Actually, I'm quite interested in reading this as I write it, because I've never explicitly anlayzed it before.

I find I'm typically happiest and most productive when I go to sleep and wake up as I wish. Normally for me this is sleep around 23h or 24h and waking up around 9h-ish. Of course, having to work an 8-hour day in the middle of my 14-15 waking hours only leaves me with 6-7 hours for commuting, cooking, eating, working on side projects, working out and spending time with my fiancee. Unfortunately, I often while away the hours working on side projects to the neglect of the rest of the things I care about. :\ When I do this, I often stay up well past midnight, so I get less sleep. My schedule winds up being something like: sleep from 2am to 7:30am, prep + commute + work + commute until about 6pm, eat and veg with fiancee until about 8pm, then work on side projects until 2am.

When I was drinking caffeine I did!

That stuff is particularly bad for me, so I'm off it totally. I definitely feel more energetic over the course of the day than I did drinking as much caffeine as I could. Or anything in-between.