Listing each branch and its last revision's date in Git

Question

I need to delete old and unmaintained branches from our remote repository. I\'m trying to find a way with which to list the remote branches by their last modified date, and

Answer 1

Sorted remote branches and the last commit date for each branch.

for branch in `git branch -r | grep -v HEAD`;do echo -e `git show --format="%ci %cr" $branch | head -n 1` \\t$branch; done | sort -r