javaScriptは2つの日付の日数の差を計算します.

//        ，    
   function  DateDiff(sDate1,  sDate2){    //sDate1 sDate2 2006-12-18    
       var  aDate,  oDate1,  oDate2,  iDays  
       aDate  =  sDate1.split("-")  
       oDate1  =  new  Date(aDate[1]  +  '-'  +  aDate[2]  +  '-'  +  aDate[0])    //   12-18-2006    
       aDate  =  sDate2.split("-")  
       oDate2  =  new  Date(aDate[1]  +  '-'  +  aDate[2]  +  '-'  +  aDate[0])  
       iDays  =  parseInt(Math.abs(oDate1  -  oDate2)  /  1000  /  60  /  60  /24)    //              
       return  iDays  
   }    

function GetDateDiff(startDate,endDate)  
   {  
       var startTime = new Date(Date.parse(startDate.replace(/-/g,   "/"))).getTime();     
       var endTime = new Date(Date.parse(endDate.replace(/-/g,   "/"))).getTime();     
       var dates = Math.abs((startTime - endTime))/(1000*60*60*24);     
       return  dates;    
   }