日期操作

//初始化

var thisday=new Date();

var thisday2=new Date("08/09/1999");//月/日/年

var thisday3=new Date("08/09/1999 20:15:15");

 

//取当前日期

var date = new Date();
var now =date.getFullYear() + "-" + (date.getMonth() + 1) + '-' + date.getDate();

//字符串转日期类型
    function strToDate(str)
    {
      return new Date(str.split("-").join("/"));
    }

//计算天数差的函数
   function  DateDiff(date1,date2){
       var difference = Date.UTC(date2.getYear(),date2.getMonth(),date2.getDate(),0,0,0)
                    - Date.UTC(date1.getYear(),date1.getMonth(),date1.getDate(),0,0,0);
     return difference/1000/60/60/24;
   }

//得到前N天或后N天的日期 window.alert("明天是："+showdate(1));
    function showdate(n)
    {
    var uom = new Date(new Date()-0+n*86400000);
    uom = uom.getFullYear() + "-" + (uom.getMonth()+1) + "-" + uom.getDate();
    return uom;
    }

//DateAdd("d",1,now)

function   DateAdd(strInterval,   NumDay,   dtDate)   { 
              var   dtTmp   =   new   Date(dtDate);
              if   (isNaN(dtTmp))   dtTmp   =   new   Date(); 
              switch   (strInterval)   { 
              case   "s":
                   dtTmp  =   new   Date(Date.parse(dtTmp)   +   (1000   *   NumDay));
                break;
              case   "n":
                   dtTmp  =   new   Date(Date.parse(dtTmp)   +   (60000   *   NumDay));
                break;
              case   "h":
                   dtTmp  =   new   Date(Date.parse(dtTmp)   +   (3600000   *   NumDay));
                break;
              case   "d":
                   dtTmp  =   new   Date(Date.parse(dtTmp)   +   (86400000   *   NumDay));
                break;
              case   "w":
                   dtTmp  =   new   Date(Date.parse(dtTmp)   +   ((86400000   *   7)   *   NumDay));
                break;
              case   "m":
                   dtTmp  =   new   Date(dtTmp.getFullYear(),   (dtTmp.getMonth())   +   NumDay,   dtTmp.getDate(),   dtTmp.getHours(),   dtTmp.getMinutes(),   dtTmp.getSeconds());
                break; 
              case   "y":
                   dtTmp  =   new   Date((dtTmp.getFullYear()   +   NumDay),   dtTmp.getMonth(),   dtTmp.getDate(),   dtTmp.getHours(),   dtTmp.getMinutes(),   dtTmp.getSeconds());
                break;
              }
              var mStr=new String(dtTmp.getMonth()+1);
              var dStr=new String(dtTmp.getDate());
              return dtTmp.getFullYear()+"-"+mStr+"-"+dStr;
  }