The Date::Calc module provides the Delta_Days method. It should be possible to calculate the difference between two days. E.g.:

use Date::Calc qw/Delta_Days/;

my $date1 = '27/01/03';
my $date2 = '01/02/03';

my $delta = Delta_Days(map {reverse split m:/:} ($date1, $date2));
print $delta;
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