ie js new date

//+---------------------------------------------------  
//| 求两个时间的工作日天数差 日期格式为 YYYY-MM-dd   
//+---------------------------------------------------  
function daysWorkBetween(DateOne,DateTwo)  
{   
  var OneMonth = DateOne.substring(5,DateOne.lastIndexOf ('-'));  
  var OneDay = DateOne.substring(DateOne.length,DateOne.lastIndexOf ('-')+1);  
  var OneYear = DateOne.substring(0,DateOne.indexOf ('-'));  
 
  var TwoMonth = DateTwo.substring(5,DateTwo.lastIndexOf ('-'));  
  var TwoDay = DateTwo.substring(DateTwo.length,DateTwo.lastIndexOf ('-')+1);  
  var TwoYear = DateTwo.substring(0,DateTwo.indexOf ('-'));  
  var dddddd1=NewDate(DateOne);
  var dddddd2=NewDate(DateTwo);
  
 var days=0;//统计日期
  var btwDate=Date.parse(dddddd1)/86400000;
//ie不支持date.parse(new Date(DateOne))
  var d1 = Date.parse(dddddd1)/86400000;
  var d2=Date.parse(dddddd2)/86400000;
  for (; btwDate<d2; btwDate++) {
      //格式化日期
    //使用方法 
      var formatate = new Date(btwDate*86400000);
      formatate = formatate.format("yyyy-MM-dd"); 
//      formatate= formatate.getFullYear()+"-"+(formatate.getMonth()+1)+"-"+formatate.getDate();
      if (checkWorkDay(formatate)) {
          days++;
    }
}
  return Math.abs(days);  
}  
function NewDate(str) { 
//针对ie不支持new date
    str = str.split('-'); 
    var date = new Date(); 
    date.setUTCFullYear(str[0], str[1] - 1, str[2]); 
    date.setUTCHours(0, 0, 0, 0); 
    return date; 
    }