#!perl
use strict;
use warnings;
use feature 'say'; # Perl 5.10.0 and later
use autodie; # makes chdir and open failures fatal errors
use File::DosGlob 'glob'; # changes glob() to use DOS wildcards

my $dir = "c:/perl/logs";
my @dates;

chdir $dir;
for my $filename (grep {-f} glob '2010*') {
    open my $fh, '<', $filename;
    while (<$fh>) {
        if (my ($date) = /\bdate=(\d{1,4}-\d{1,2}-\d{1,2})/i) {
            push @dates, $date;
        }
    }
}

say for @dates;
[download]