Simple function to calculate the due date based on an invoice date and terms ID.

NetSuite_DueDateCalculation.js

  function calculateDueDate(termID,invDate){
    var dueDate=''
    try{
      var daysToAdd=search.lookupFields({type:'term',id:termID,columns:['daysuntilnetdue']}).daysuntilnetdue;
      dueDate=new Date(format.parse({value:invDate,type:format.Type.DATE}));
      dueDate.setDate(dueDate.getDate()+parseInt(daysToAdd));
    }catch(err01){
      log.error('calculateDueDate.err01',JSON.stringify(err01));
      handleErrorAndSendNotification(err01,'calculateDueDate');
    }finally{
      return dueDate;
    }
  }