=head2 daysBetween

    my $daysBetween = $calendar->daysBetween($startdate, $enddate)

C<$startdate> and C<$enddate> are C4::Dates objects that define the interval.

Returns the number of non-holiday days in the interval.

useDaysMode syspref has no effect here.

=cut

sub daysBetween ($$$) {

    my $self      = shift or return undef;

    my $startdate = shift or return undef;

    my $enddate   = shift or return undef;

	my ($yearFrom,$monthFrom,$dayFrom) = split("-",$startdate->output('iso'));

	my ($yearTo,  $monthTo,  $dayTo  ) = split("-",  $enddate->output('iso'));

	if (Date_to_Days($yearFrom,$monthFrom,$dayFrom) > Date_to_Days($yearTo,$monthTo,$dayTo)) {

		return 0;

		# we don't go backwards  ( FIXME - handle this error better )

	}

    my $count = 0;

    while (1) {

        ($yearFrom != $yearTo or $monthFrom != $monthTo or $dayFrom != $dayTo) or last; # if they all match, it's the last day

        unless ($self->isHoliday($dayFrom, $monthFrom, $yearFrom)) {

            $count++;

        }

        ($yearFrom, $monthFrom, $dayFrom) = &Date::Calc::Add_Delta_Days($yearFrom, $monthFrom, $dayFrom, 1);

    }

    return($count);

}

-