var day="";
var month="";
var ampm="";
var ampmhour="";
var myweekday="";
var year="";
mydate=new Date();
myweekday=mydate.getDay();
mymonth=mydate.getMonth()+1;
myday= mydate.getDate();
myyear= mydate.getYear();
year=(myyear > 200) ? myyear : 1900 + myyear;
if(myweekday == 0)
weekday=" 星期日 ";
else if(myweekday == 1)
weekday=" 星期一 ";
else if(myweekday == 2)
weekday=" 星期二 ";
else if(myweekday == 3)
weekday=" 星期三 ";
else if(myweekday == 4)
weekday=" 星期四 ";
else if(myweekday == 5)
weekday=" 星期五 ";
else if(myweekday == 6)
weekday=" 星期六 ";

BirthDay=new Date("February 6,2012");//改成你的计时日期
today=new Date();
timeold=(today.getTime()-BirthDay.getTime());
msPerDay=24*60*60*1000
e_daysold=(timeold/(msPerDay*7))+1
daysold=Math.floor(e_daysold);

document.write(year+"年"+mymonth+"月"+myday+"日 "+weekday+"[第<b><font color=red>"+daysold+"</b></font>周]");