http://www.perlmonks.org?node_id=1015588


in reply to Re^2: Delete all but the most recent backup file
in thread Delete all but the most recent backup file

I guess you'd have to replace the line
map { my ( $d, $m, $y ) = /(\d+)/g; [ $_, "$y$m$d" ] }
by something like
map {[$_, -M $_]}
However, currently I'm not often using these functions, so of course you should test it first, not that you end up keeping the oldest instead of the newest backup...