bitbucket - checkout by date

At work, we decided to upgrade the system and we did not tag the old version in bitbucket (since we were planning to upgrade definitely).. However, due to some extra work and time restriction the team could not able to achieve the goal and we decided to return back to an old version by date. To do this,
- open SourceTree
- open git with Terminal icon and run the command  git checkout 'master@{2014-04-01}'

- create a branch for the detached head.

https://answers.atlassian.com/questions/245850/how-to-run-a-git-command-as-a-custom-action
http://stackoverflow.com/questions/6990484/git-checkout-by-date
https://answers.atlassian.com/questions/263451/branches-for-commit-git