object - I am having trouble with an if function, I am trying to build a small module and a comparion operator is not functioning -

i trying build small module can automate gantt chart. color cells within date range , color weekends differently. however, specific section giving me trouble.

if (celldate>=schstartdate && celldate<=schenddate){ if(celldate.getday()>=1 && celldate.getday()<=5){   sheet.getrange(j,k).setbackground("#9193ff");  }   else      sheet.getrange(j,k).setbackground("#f2f4d9");    if (celldate==schstartdate && sheet.getrange(2,k).getvalue() == startshift){sheet.getrange(j,k).setbackground("red");} 

while first sections works perfectly, second section "==" operator not giving desired result. in the section above "equal to" condition works absolutely fine , colors cell expected same "equal to" condition doesnt seem work in

 if (celldate==schstartdate && sheet.getrange(2,k).getvalue() == startshift) {sheet.getrange(j,k).setbackground("red");} 

the entire code below

function plannedganttchart(){  var ui = spreadsheetapp.getui(); var ss = spreadsheetapp.getactivespreadsheet() ss.setactivesheet(ss.getsheetbyname("search"));  var sheet = spreadsheetapp.getactivesheet(); var startrow = 2; var numrows = spreadsheetapp.getactivespreadsheet().getlastrow(); var startcolumn=1; var numcolumns = spreadsheetapp.getactivespreadsheet().getlastcolumn();  sheet.getrange("n3:bw65").setbackground("white"); //recolors entire sheet  (i=1;i<=numcolumns-124;i++){ if(sheet.getrange(2,i).getvalue()=="planned start date"){   var startdatecolumn=i;  }              //assigns column containing planned start date if(sheet.getrange(2,i).getvalue()=="days"){   var shiftcolumn=i;     }             //assigns column containing shifts if(sheet.getrange(2,i).getvalue()=="planned end date"){   var enddatecolumn=i;           } //assigns column containing planned end date  }   // section allocates planned start date day , shift     (j=3; j<=numrows; j++) {    var plannedstartdate = new     date(sheet.getrange(j,startdatecolumn).getvalue()); var startdate = plannedstartdate.getdate(); var starthour = plannedstartdate.gethours(); if (starthour>=6 && starthour<16)   var startshift="am" //allocates shift based on hour else if(starthour>=16 && starthour <=23)   var startshift="pm"; // allocates pm shift based on hour else if(starthour>=0 && starthour <=2){   startdate=startdate-1; // if dates falls after midnight docks start date 1 , assigns pm shift   var startshift="pm"; }    // section allocates planned end date day , shift            var plannedenddate=new date(sheet.getrange(j,enddatecolumn).getvalue());    var enddate = plannedenddate.getdate();    var endhour = plannedenddate.gethours();     if (endhour>=6 && endhour<16){   var endshift="am"; //allocates shift based on hour } else if (endhour>=16 && endhour<=23){   var endshift = "pm"; // allocates pm shift based on hour } else if (endhour>=0 && endhour<=2){   enddate = enddate-1; //dates falls after midnight docks start date 1 , assigns pm shift   endshift = "pm"; }  if(math.round(sheet.getrange(j,shiftcolumn).getvalue()*2)<(sheet.getrange(j,shiftcolumn).getvalue()*2)) // calculates number of required shifts var shifts= math.round(sheet.getrange(j,shiftcolumn).getvalue()*2)+1; else   var shifts =math.round(sheet.getrange(j,shiftcolumn).getvalue()*2);    var schstartdate= new date(plannedstartdate.getfullyear(),plannedstartdate.getmonth(),startdate);   var schenddate= new date(plannedenddate.getfullyear(),plannedenddate.getmonth(),enddate);   var shiftcount=0; //initializes counter of shift    // potential error area, section,   (k=14;k<=75;k++){  //k=14 reflect column number of grid    var tempdate1=new date(plannedstartdate.getfullyear(),plannedstartdate.getmonth(),sheet.getrange(1,k).getvalue());   var tempdate2=new date(plannedstartdate.getfullyear(),plannedstartdate.getmonth()+1,sheet.getrange(1,k).getvalue());     if (tempdate1 >= schstartdate && tempdate1 <= schenddate)       celldate = tempdate1;   else       celldate = tempdate2;     if (celldate>=schstartdate && celldate<=schenddate){     if(celldate.getday()>=1 && celldate.getday()<=5){       sheet.getrange(j,k).setbackground("#9193ff");  }       else          sheet.getrange(j,k).setbackground("#f2f4d9");        if (celldate==schstartdate && sheet.getrange(2,k).getvalue() == startshift){sheet.getrange(j,k).setbackground("red");}    }       /*if(sheet.getrange(1,k).getvalue() == startdate && sheet.getrange(2,k).getvalue() == startshift){     sheet.getrange(j,k).setbackground("#9193ff"); //shades background color blue of starting shift     shiftcount++; //increases counter of shifts allocated     sheet.getrange(j,k).setvalue(shiftcount);   }   else {    if(shiftcount>0 && (sheet.getrange(1,k).getvalue()<=enddate|| shiftcount<=shifts)){     if(celldate.getday()>=1 && celldate.getday()<=5){       sheet.getrange(j,k).setbackground("#9193ff"); //sequentially runs across cells changing them planned color       shiftcount++;        sheet.getrange(j,k).setvalue(shiftcount);     } //increases counter of shifts allocated     else{       sheet.getrange(j,k).setbackground("#f2f4d9");     sheet.getrange(j,k).setvalue(shiftcount);} //colours weekends separately falls shift     if(shiftcount>0 && sheet.getrange(1,k).getvalue()==enddate && sheet.getrange(2,k).getvalue()=="pm" && endshift=="am"){       sheet.getrange(j,k).setbackground("white");     sheet.getrange(j,k).setvalue(shiftcount);     shiftcount--;     }     }*/   } // k loop close bracket      //sheet.getrange(j,13).setvalue(shiftcount); // assigns number of shifts iterated    } // j loop close bracket }   //function close bracket