For this task, I would suggest using the Time::Local module to convert your beginning and end dates to epoch time, and the File::Find module to find files whose modification time (found using stat) is between the start time and end time.
Thanks for the reply. The only problem with that is that a file contaning data for 20010201 is actually created sometime the following day. Or, am I not understanding something?
Perhaps I am not understanding something. You wrote "I want to 'do something' to files created within a certain range of dates, inclusively." Is that not what you meant?
Either way, you can still use Time::Local and compare your dates in epoch time.
Another option is storing your dates in YYYYMMDD format (as you're already doing); then you can just compare them numerically.
if ($begin_date <= $curr_date and $curr_date <= $end_date) {
print "$curr_date is between $begin_date and $end_date.\n";
}