//calendar.php

<?                                                                         
 /*******************************                                          
  *   用来判断是否闰年的函数    *                                          
  *   可以根据更复杂的算法改进  *                                          
  *******************************/                                         
  function leap_year($year)                                                
    {                                                                 
      if($year% 4 == 0) // basic rule                                      
            {                                                              
             return true; // is leap year                                  
            }                                                              
   else         &nb