When you open your Time Machine backup folder on the Time Machine volume, you can still see each individual directory, so wherever your Git repositories are stored as bare repos, you will be able to find and copy them.
You can also archive a Git repository with the git archive command.
git archive -o archive.zip master If you want to do that for all branches, you could do something like:
for branch in $(git for-each-ref --format='%(refname)' refs/heads/); do git archive -o "$.zip" $branch done The substitution $ will convert refs/heads/master to master by stripping the longest match of */ from the beginning of the string.
This is inspired by a Stack Overflow question about iterating through branches.