凯撒日期（求某一天是这一年的第几天）

 
/***********************************************************
变 量 名：$year ,$month ,$day为前台提交的值
  
作    者：shyhero
  
E - mail：shyhero@outlook.com
************************************************************/
  
<?php
    $year =$_POST ['year'];
    $month =$_POST ['month'];
    $day =$_POST ['day'];
      
    $sum =0 ;
    if(month>12)
        return;
    switch($month-1)
    {
        case 12:$sum +=31;
        case 11:$sum +=30;
        case 10:$sum +=31;
        case 9:$sum +=30;
        case 8:$sum +=31;
        case 7:$sum +=31;
        case 6:$sum +=30;
        case 5:$sum +=31;
        case 4:$sum +=30;
        case 3:$sum +=31;
        case 2:
            if( ! ( $year % 4 ) && ( $year % 100 ) || ! ($year % 400))
                $sum +=29;
            else
                $sum +=28;
        case 1:$sum +=31;break;
        default: return;
    }
      
    echo $sum+$day;
?>