my $user_start_date = get_secs_from_opt( $opt{start} );
my $user_end_date = get_secs_from_opt( $opt{end} );

for my $record ( @data_records ) {
    my $rec_date = get_secs_from_data( $record );
    if ( $rec_date >= $user_start_date and $rec_date <= $user_end_date ) {
        # do something with a hit...
    }
}