The shell-command example would make more sense to us if you put code tags around it (<c>…</c>).
in reply to Perl script to find the file count in subdirectories in a time interval
As indicated in the first reply above, your question is not clear. What have you tried in perl so far?
In terms of a perl script that gathers and reports information about quantities of things in a directory structure, you might want to look at a tool I posted here a while back: Get useful info about a directory tree -- it has command line options for specifying a date range of interest.