Javascript计算到今天为止今年过去了多少天

 

var day=today.getDate();
var sum=0
switch(month)
{
  case 0:sum=0;break;
　case 1:sum=31;break;
　case 2:sum=59;break;
　case 3:sum=90;break;
　case 4:sum=120;break;
　case 5:sum=151;break;
　case 6:sum=181;break;
　case 7:sum=212;break;
　case 8:sum=243;break;
　case 9:sum=273;break;
　case 10:sum=304;break;
　case 11:sum=334;break;
　default:document.write("error")
}
sum=sum+day;
if(year%400==0||(year%4==0&&year%100!=0))
 leap=1;
else
 leap=0;
if(leap==1&&month>2)
 sum++;
document.write("<h1>亲，今天是:</h1>")
document.write(year+" ")
document.write(month+1)
document.write(" "+day)
οnlοad=date_alert()

</script>
</body>
</html>