var ACQ = this.getField("Acquired_Date").value; //user-entered, purchase date of vehicle
var ARPD = this.getField("Advanced_Renewal_Period_Date").value;//calculated in that field, 90 days before customer's current year birthday
var oDOB = this.getField("BirthDate").valueAsString;//user-entered, Date of Birth
var cbBiennial = this.getField("Biennial").value;//checked if customer chooses 2-year registration period, otherwise calculations below consider a 1-year registration period

if(oDOB !== "") { //testing for user-entered BirthDate

var cDOB = util.scand("mm/dd/yy", oDOB.slice(0,6));//creating current Date of Birth
var dACQ = util.scand("mm/dd/yy", ACQ);//creating Acquired Date
var dARPD = util.scand("mm/dd/yy", ARPD);//creating date 90 days before current year Date of Birth
var msRPSY = cDOB.getTime() - dACQ.getTime();//user-entered DOB follows user-entered Acquired Date in the Same Year (ex. cDOB = 11/02/2021, dACQ = 02/25/21 would be 9 month difference)
var ONEDAY = (24 * 60 * 60 * 1000);//millisecond to day conversion
var dRPSY = msRPSY/ONEDAY;//period in days between dACQ and cDOB
dRPSY = Math.floor(dRPSY);//round down
var ONEMONTH = (31 * 24 * 60 * 60 * 1000);//millisecond to month conversion
var moRPSY = msRPSY/ONEMONTH;//period in months between dACQ and cDOB
var ONEYEAR = (12 * 31 * 24 * 60 * 60 * 1000);//millisecond to year conversion
var yRPSY = msRPSY/ONEYEAR;//period in years between dACQ and cDOB

var msRPNY = dACQ.getTime() - cDOB.getTime();//user-entered DOB follows user-entered Acquired Date in the Next Year (ex. dACQ = 11/02/2020, cDOB = 02/25/21 would be 4 month difference)
var dRPNY = msRPNY/ONEDAY;//period in days between dACQ and cDOB
dRPNY = Math.floor(dRPNY);//round down
var moRPNY = msRPSY/ONEMONTH;//period in months between dACQ and cDOB
var yRPNY = msRPNY/ONEYEAR;//period in years between dACQ and cDOB

var msARPD = dARPD.getTime();//convert to milliseconds
var msDOB = cDOB.getTime();//convert to milliseconds 
var msRGRNP = msDOB + msARPD;//add to get Registration Renewal Period in milliseconds 

var YREGP = cDOB;
YREGP.setFullYear(cDOB.getFullYear() + 1);
var YYREGP = cDOB;
YYREGP.setFullYear(cDOB.getFullYear() + 2);

var msYREGP = YREGP.getTime(); 
var msXRGP = msYREGP + msRGRNP; 
var moXRGP = msXRGP / ONEMONTH;


var msYYREGP = YYREGP.getTime(); 
var msXXRGP = msYYREGP + msRGRNP; 
var moXXRGP = msXXRGP / ONEMONTH; 
}

else if (cDOB > dACQ) {event.value = moRPSY;}
else if (cDOB < dACQ) {event.value = moRPNY;}
else if ((dARWP < dACQ < cDOB) && (cbBiennial === "Off")) {event.value = moXRGP;}
else if ((dARWP < dACQ < cDOB) && (cbBiennial !== "Off")) {event.value = moXXRGP;}