captainslog is a command line utility that prints git logs by day and by author. This is useful when filling out time logs and emailing summaries of commits to clients.
gem install captainslog
Within a git repository:
$ captainslog
> prints out the past 7 formatted day logs including today
$ captainslog 2
> prints out the past 2 formatted day logs including today
$ captainslog 20
> prints out the past 20 formatted day logs including today