A more detailed analysis could also take in account the number of changes. How many files per commit? How many lines, maybe?
The day of week is also a very interesting metric, that is very visible e.g. on github's timeline. I know my busiest days in terms of commits are in the middle of the week, a marked decrease on Friday afternoons, and if there are commits in the weekend, they most likely contain swearing in the message.
Edit: I'm betting Brad Fitzpatrick's pattern in Go (current job?) and memchached (not current job?) would vary in terms of day of week, not just hour.