I'm not sure of the git command for it yet, but I think you can find them in the reflogs.
.git/logs/refs/heads/<yourbranch>
My files appear to have a unix timestamp in them.
Update: There appears to be an option to use the reflog history instead of the commit history when printing the logs:
git log -g
You can follow this log as well, back to when you created the branch. git log
is showing the date of the commit, though, not the date when you made the action that made an entry in the reflog. I haven't found that yet except by looking in the actual reflog in the path above.