Regenerate all tags with date set to that of the commit that was tagged

retag-with-date

#!/bin/bash

# This script will regenerate every tag in a repository, setting the
# creation date of the tag to that of the commit that the tag is
# attached to. The message for the tag is set to the static string
# 'End of unit'.

git tag | while read tag;
do
  git checkout ${tag}
  git tag -d ${tag}
  git push origin :refs/tags/${tag}
  GIT_COMMITTER_DATE="$(git show --format=%aD | head -1)" git tag -m 'End of unit' ${tag}
done