Populating date from one apex:inputText to another using Javascript

If you want to set new date on apex:inputText by referencing date from other element you can do it by using javascript. You don't need to use apex date methods.

 function functionreadOnly(Index,SecondElementId){  
      var idToDate;  
      var valueToDate;  
      if(Index != 0){  
           idToDate = SecondElementId.replace(Index + ":SecondElementId",Index-1 + ":FirstElementId");  
           valueToDate = document.getElementById(idToDate).value;  
           var Obj = document.getElementById(SecondElementId);  
           var dayAfter = new Date(valueToDate);   
           dayAfter.setDate(dayAfter.getDate()+1);  
           var finalEndDate = (dayAfter.getMonth() + 1) + '/' + dayAfter.getDate() + '/' + dayAfter.getFullYear() ;  
           Obj.value = finalEndDate;        
           //Making element read only  
           if(Obj.value.length != 0){  
                Obj.readOnly = true   
           }  
      }  
 }