This is precisely the kind of thing that can be easily solved in a few lines of Perl. Here's one way to do it:
-- Using perldoc
There are 2 commands, depending of the kind of perl module:
This Perl subroutine calculates and returns the amount of days between two yyyymmdd formatted dates:
This is just a quick simple example of scraping a html page's content and turning it into something else (RSS) using Perl regular expressions and the XML::RSS module.
This Perl script loops through the files in the specified directory: