Welcome to the Perl community, clementine.

The stat command will return, among a number of other things, the creation time of a file (on Windows only) and the modification time of a file (see porting information for details). You can get directory contents using opendir, readdir and closedir. And you can compare the strings using either substr and Equality Operators or, if you are feeling more adventurous, regular expressions. I'll be happy to take a look at any code you cobble together to give more specific advice.