Time::Local can convert your individual time fields (year, month, date, hour, etc) back into an epoch time which you can use to compare with the number returned by time().

Of course you might want to use a regular expression to split your log filename into individual fields first..

Update: pg's answer below is the best one I think; the great thing about time strings in yymmddhhmmss format is that they are easy to use for string sorting/comparisons..