js 比较时间大小

var beginTime = "2009-09-21 00:00:00";   
var endTime    = "2009-09-21 00:00:01";   
var beginTimes = beginTime.substring(0,10).split('-');   
var endTimes   =  endTime.substring(0,10).split('-');   

beginTime = beginTimes[1]+'-'+beginTimes[2]+'-'+beginTimes[0]+' '+beginTime.substring(10,19);   
endTime    = endTimes[1]+'-'+endTimes[2]+'-'+endTimes[0]+' '+endTime.substring(10,19);   

alert(beginTime+"aaa"+endTime);   
alert(Date.parse(endTime));   
alert(Date.parse(beginTime));   

var a =(Date.parse(endTime)-Date.parse(beginTime))/3600/1000;   
if(a<0){   
    alert("endTime小!");   
}else if (a>0){   
    alert("endTime大!");   
}else if (a==0){   
    alert("时间相等!");   
}else{   
           return 'exception'}   
 } 

本文转载自：http://zkliqiang.iteye.com/blog/965150