greenhat is a quick hack for decorating your GitHub contribution calendar with commits for the past n days. It uses the GIT_AUTHOR_DATE and GIT_COMMITTER_DATE environmental variables to make commits appear in the past. Be warned that greenhat will clobber your repository's commit history.
Place greenhat.py in your Git repository. Make sure your remote repository URL is set, and that you have a public SSH key set up. Then run the script with the python interpreter, with an integer specifying n number of days before today to generate commits for. E.g.,
python greenhat.py <n>
It might take a while to generate all the commits. If greenhat stops before it finishes, you can resume where you last left off by specifying a date before today when you want it to resume, like so:
python greenhat.py <n> <date>
n is the remaining days you want to generate commits for, and date is a date string in the form yyyy-mm-dd (e.g., 2013-04-05).
The following calendar is the result of running python greenhat.py 365:
The run took a total of eight hours. Beautiful, isn't it?
Enjoy your decorated calendar!
greenhat is distributed under the GNU General Public License v3.0 (GPLv3).