PHP生成月历代码

<?php
/*
Function Written by Nelson Neoh @3/2004.
For those who wants to utilize this code, please do not remove this remark.
If you have done any enhancement to this code, please post the copy at http://www.dev-club.com PHP board. Thank you.

Function usage: calendar(Month,Year)
*/

function calendar($MM,$YYYY){
if($MM=="") $MM = date("m");
if($YYYY=="") $YYYY = date("Y");
if(checkdate($MM,1,$YYYY)){
$stringDate = strftime("%d %b %Y",mktime (0,0,0,$MM,1,$YYYY));
$days = strftime("%d",mktime (0,0,0,$MM+1,0,$YYYY));
$firstDay = strftime("%w",mktime (0,0,0,$MM,1,$YYYY));
$lastDay = strftime("%w",mktime (0,0,0,$MM,$days,$YYYY));
$printDays = $days;
$preMonth = strftime("%m",mktime (0,0,0,$MM-1,1,$YYYY));
$preYear = strftime("%Y",mktime (0,0,0,$MM-1,1,$YYYY));
$nextMonth = strftime("%m",mktime (0,0,0,$MM+1,1,$YYYY));
$nextYear = strftime("%Y",mktime (0,0,0,$MM+1,1,$YYYY));
print("<table border=\"1\" cellpadding=\"1\" cellspacing=\"1\">");
print("<th valign=\"top\"><a href=\"".$_SERVER['PHP_SELF']."?NB=".$_GET["NB"]."&MM;=".$preMonth."&YY;=".$preYear."\">P");
print("<th colspan=\"5\" valign=\"top\">".strftime("%b %Y",mktime (0,0,0,$MM,1,$YYYY))."");
print("<th valign=\"top\"><a href=\"".$_SERVER['PHP_SELF']."?NB=".$_GET["NB"]."&MM;=".$nextMonth."&YY;=".$nextYear."\">N");
print("<tr style=\"font-family: Verdana; font-size:x-small\">");
print("SunMonTueWedThuFriSat");

    $currentDays = 1;   
    for($a=1;$a<=5;$a++){   
        print("<tr align=\"left\" valign=\"top\" style=\"font-family: Verdana; font-size:x-small\">");   
        $diffDays = $firstDay-$lastDay;   
        if($firstDay>$lastDay && $currentDays ==1 && ($diffDays<>1)){   
            for($x=$lastDay;$x>=0;$x--){   
                $printDays = $days-$x;   
                print("<td>$printDays</td>");   
            }   
            for($z=1;$z<$firstDay-$lastDay;$z++){   
                print("<td> </td>");   
            }   
            for($y=$firstDay;$y<7;$y++){   
                print("<td>$currentDays</td>");   
                $currentDays++;   
            }   
        } elseif($firstDay!=0 && $currentDays==1){   
            for($z=1;$z<=$firstDay;$z++){   
                print("<td> </td>");   
            }   
            for($y=$firstDay;$y<7;$y++){   
                print("<td>$currentDays</td>");   
                $currentDays++;   
            }   
        } else {   
            for($u=1;$u<=7 && $currentDays<=$days;$u++){   
                print("<td>$currentDays</td>");   
                $currentDays++;   
            }   
        }   
        print("</tr>");   
    }   
    print("</table>");   
}   

}
?>