my $mod_time = (stat($file_path))[9];
my $date = strftime "%Y_%m_%d", localtime($mod_time);
my ($year, $month, $day) = split('_', $date);
# ...
$new_file_name = "${year}_${month}_${day}_$count.jpg";

##</code><code>##

my $mod_time = (stat($file_path))[9];
my $date = strftime "%Y_%m_%d", localtime($mod_time);
# ...
$new_file_name = "${date}_$count.jpg";

##</code><code>##

move($file_path, "$dest_dir/$new_file_name") or die "Failed to move file $file_path: !\n";
unlink $file_path or warn "Failed to delete original file $file_path: $!\n";