+ # add a good recommended exec date
+ # set to skonto date if exists or to duedate
+ # in both cases subtract the same buffer (if configured, default 0)
+ $bt->{recommended_execution_date} =
+ $set_skonto_date && $bt->{payment_type} eq 'with_skonto_pt' ?
+ DateTime->from_kivitendo($bt->{skonto_date})->subtract(days => $subtract_days)->to_kivitendo
+ : $set_duedate && $bt->{duedate} ?
+ DateTime->from_kivitendo($bt->{duedate} )->subtract(days => $subtract_days)->to_kivitendo
+ : undef;
+
+