2 of 9 added 470 characters in body

With zsh:

echo rm -rf follower<->(/m+13om[2,-1])

(remove echo when happy)

  • <-> any sequence of decimal digits (a short form of <1-20> be without bound).
  • (...): glob qualifier
  • /: only select files of type directory (equivalent of find's -type d)
  • m+13: files whose age in whole days is strictly greater than 13 days, so files that are 14 days old or older (equivalent of find's -mtime +13).
  • om: order by modification time (like ls -t younger files first)
  • [2,-1]: only from the 2nd youngest to the oldest.