How to find date difference in javascript_javascript skills

The example in this article describes how to find the date difference in JavaScript. Share it with everyone for your reference, the details are as follows:

<script type="text/javascript">
function daytonow(year, month, date){
 //思路就是转换两个日期为时间戳即毫秒数，再除以每一天的毫秒数得出相隔多少天
 //JS中的month是从0开始，所以month要减一
 month--;
 //过去的日子
 var tdate = new Date(year, month, date).getTime();
 //今天
 var tnow = new Date().getTime();
 var longdate = Math.ceil((tnow - tdate) / (1000 * 60 * 60 * 24));
 return longdate;
}
alert(daytonow(2009, 4, 5));
</script>

The difference in days between the two dates:

//两日期串的天数之差, 前-后, sDate1-sDate2
function DateDiff(sDate1, sDate2) { //sDate1和sDate2是"2002-12-18"格式
  var aDate, oDate1, oDate2, iDays;
  aDate = sDate1.split("-");
  oDate1 = new Date(aDate[0], aDate[1] - 1, aDate[2]);
  aDate = sDate2.split("-");
  oDate2 = new Date(aDate[0], aDate[1] - 1, aDate[2]);
  iDays = parseInt(Math.abs(oDate1 - oDate2) / 1000 / 60 / 60 / 24);
  if ((oDate1 - oDate2) < 0) {
    return -iDays;
  }
  return iDays;
}
//两日期串的天数之差, 前-后, sDate1-sDate2
function DateDiff2(sDate1, sDate2) { //sDate1和sDate2是"12/18/2011"格式
  var oDate1, oDate2, iDays;
  oDate1 = new Date(sDate1);
  oDate2 = new Date(sDate2);
  var iDays = parseInt(Math.abs(oDate1 - oDate2) / 1000 / 60 / 60 / 24);
  if ((oDate1 - oDate2) < 0){
    return -iDays;
  }
  return iDays;
}

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I hope this article will be helpful to everyone in JavaScript programming.