//离下一个圣诞节还有多少天

var christ=new Date();

christ.setMonth(11);

christ.setDate(25);

var year=now.getFullYear();

var diff=christ-now;

var time;

if(diff<0){

 christ.setFullYear(year+1);

 diff=christ-now;

}

time=Math.ceil(1.0*diff/(1000*3600*24));

document.write("离下一个圣诞节还有："+time+"天");