Data visualization - 9 Years of Sleep

I would love to have access to gmail's log data to check something similar (I study sleep). In my case, the first thing I do when I wake up and the last thing before going to bed is checking my email. I bet I am not the only one.

This site does something similar based on when you tweet. It's reasonably accurate for me: http://www.sleepingtime.org/nahurst

I used to adjust my sleep schedule on weekends like he does towards the end of the chart, but I have recently lost that ability. (I think I stopped caring what time it was, so I lose/gain just about two hours a day now. This gives me one day every two weeks where I am awake at 9am :)

Someone should do this analysis with HN comment posting times. I only use IRC for being productive, which is not necessarily indicative of when I am awake ;)

Genius how he determined this.

I should be able to determine something similar to this in a few years time from RescueTime, with the added bonus of how long I wasted on certain activities.

Those shifting, spiral-like patterns that are intermittent throughout the graph, I think those are his holidays (most occur at august), where he, as so many others "like us", turn his night and day around :)