for branch in `git branch -r | grep -v HEAD`; do \
    echo -e `git show --format="%cr %an" $branch | head -n 1` \\t$branch; \
  done | \
  grep -e '.. months' -e '[8-9] months' | grep 'origin/' | \
  sed 's/.*origin\///' | \
  xargs -n 1 echo git push origin --delete | bash