alch-

  */10 * * * * /usr/bin/find ~/tmp/hour/ -mindepth 1 -mmin +60 -cmin +60 -delete
  0    * * * * /usr/bin/find ~/tmp/day/ -mindepth 1 -mmin +1440 -cmin +1440 -delete
  # etc

  0 21 * * * (/usr/bin/find /Users/me/tmp/week/ -mindepth 1 -mtime +5 -ctime +5; /usr/bin/find /Users/me/tmp/month/ -mindepth 1 -mtime +28 -ctime +28; /usr/bin/find /Users/me/tmp/6months/ -mindepth 1 -mtime +183 -ctime +183) | /usr/bin/sed 's/^.Users.me.tmp.//g' | /usr/bin/mail -E -s "will delete some ~/tmp files soon" me@domain