When i started writing my dissertation, it occurred to me that it would be nice to know how much time i spent on the thing when i was finally done with it. So i made a habit of recording when i worked on that too. Now i have hundreds of little timestamped log entries.
What does one do with all this data? Visualize it, of course...
Time spent on the dissertation (orange): 327.9 hours
Time spent on the talk (purple): 41.4 hours
Total: 369.3 hours
(Made with Python and ReportLab, then marked up with OmniGraffle.)
Note 1. I also tried living on a 28-hour day (with a 6-day week) for a few weeks one summer. It was interesting. But that is a story for another time.