js实现日期的相加减

<script type="text/javascript">

 

function dateOperator(date,days,operator)

 

{

 

    date = date.replace(/-/g,"/"); //更改日期格式

    var nd = new Date(date);

    nd = nd.valueOf();

    if(operator=="+"){

     nd = nd + days * 24 * 60 * 60 * 1000;

    }else if(operator=="-"){

        nd = nd - days * 24 * 60 * 60 * 1000;

    }else{

        return false;

    }

    nd = new Date(nd);

 

    var y = nd.getFullYear();

    var m = nd.getMonth()+1;

    var d = nd.getDate();

    if(m <= 9) m = "0"+m;

    if(d <= 9) d = "0"+d; 

    var cdate = y+"-"+m+"-"+d;

    return cdate;

}

 

  

 

//相减

alert(dateOperator("2014-01-01",1,"-")) ;

//相加

alert(dateOperator("2014-01-01",1,"+")) ;

 

</script>