+sub closed_period {
+ my ($self) = @_;
+
+ # check for closed period
+ croak t8('Illegal date') unless ref $self->valutadate eq 'DateTime';
+
+
+ my $closedto = $::locale->parse_date_to_object($::instance_conf->get_closedto);
+ if ( ref $closedto && $self->valutadate < $closedto ) {
+ return 1;
+ } else {
+ return 0;
+ }
+}