var week=",不太明白这个是什么意思

 var date = new Date();  // 实例化日期对象  

  var timeStr = '';//日期 

  timeStr = date.getFullYear() + "年" ;  

  timeStr += date.getMonth() + 1 +"月";  

  timeStr += date.getDate()+"日";  

  var day  = date.getDay(); //星期 

  var week = '';

  switch(day){