Console Error Not Function, But Similar Script runs ok in another dateobject field

I have a series of three date object fields for business and for mobilehome: StartDate, EndDate, and AdvancedRenewalPeriodDate. The AdvancedRenewalPeriodDate calculates in days the difference between the EndDate field value minus 90 days. I took my scripts for these (business,mobilehome) AdvancedRenewalPeriodDate fields from the calculation script located in my original AdvancedRenewalPeriodDate used when BirthDate dateobject is involved. For some reason, my new ones (business,mobilehome) do not work. What am I missing???????  File Attached- Thanks in advance!!! 

//START DATE Registration Period for BUSINESS NOT FOR HIRE or

//SHORT TERM RENTAL JUN 01
var sACQb = this.getField("AcquiredDate").valueAsString;
if (sACQb == "") event.value = "";
else {
var dsACQb = util.scand("mm/dd/yyyy",sACQb);
dsACQb.setMonth(05);
dsACQb.setDate(01);
event.value = util.printd("mm/dd/yyyy", dsACQb);}

//END DATE Initial Registration Period for BUSINESS NOT FOR HIRE or

//SHORT TERM RENTAL MAY 31
var eACQb = this.getField("AcquiredDate").valueAsString;
if (eACQb == "") event.value = "";
else {
var deACQb = util.scand("mm/dd/yyyy",eACQb);
deACQb.setMonth(05);
deACQb.setDate(30);
event.value = util.printd("mm/dd/yyyy", deACQb);}

//businessADVANCEDRENEWALPERIODDATE BUSINESS NOT FOR HIRE or
//SHORT TERM RENTAL ENDDATE-90days
var bARP = this.getField("businessEndDate").valueAsString;
if (bARP == "") event.value = "";
else {
var dbARP = util.scand("mm/dd/yyyy", bARP);
dbARP.setDate(bARP.getDate()-90);
event.value = util.printd("mm/dd/yyyy", dbARP);}
______________________________________________________________________
//mobilehomeSTARTDATE JAN 1
var sACQmh = this.getField("AcquiredDate").valueAsString;
if (sACQmh == "") event.value = "";
else {
var dsACQmh = util.scand("mm/dd/yyyy",sACQmh);
dsACQmh.setMonth(00);
dsACQmh.setDate(01);
event.value = util.printd("mm/dd/yyyy", dsACQmh);}

//mobilehomeENDDATE DEC 31
var eACQmh = this.getField("AcquiredDate").valueAsString;
if (eACQmh == "") event.value = "";
else {
var deACQmh = util.scand("mm/dd/yyyy",eACQmh);
deACQmh.setMonth(11);
deACQmh.setDate(31);
event.value = util.printd("mm/dd/yyyy", deACQmh);}

//mobilehomeAdvancedRenewalPeriodDate ENDDATE-90days
var mhARP = this.getField("mobilehomeEndDate").valueAsString;
if (mhARP == "") event.value = "";
else {
var dmhARP = util.scand("mm/dd/yyyy", mhARP);
dmhARP.setDate(mhARP.getDate() - 90);
event.value = util.printd("mm/dd/yyyy", dmhARP);}