Basic PHP Calendar

<style type="text/css">
table {
    width:199px;
    border:0px solid #888;    
    border-collapse:collapse;
}
 
td {
    width:27px;
 font-family: Arial, sans-serif;
    border-collapse:collapse;
    border:1px solid #888;
    text-align:center;
}
 
.calblock{
 float:none;
}
 
.onecal{
 vertical-align:top;
    background-color: #E9ECEF;
 
}
.cal{
 border-style:solid;
 border-width:thin;
 border-color:#E9ECEF;
 float:left;
 padding:3px;
}
 
.days{
    background-color: #F1F3F5;
}
 
.hasday{
    background-color: #FFFFDE;
}
.noday{
    background-color: #E9ECEF;
}
 
th {
 font-family: Arial, sans-serif;
    border-collapse:collapse;
    border:1px solid #888;
    background-color: #E9ECEF;
}
</style>
 
 
<?PHP
/* 
 showCalendar( $monthToshow = null, $yearToShow = null, $firstDayOfWeek = 0 ) 
 
 Shows a single month calendar. All parameters use Day, Month and Year encodings specified by PHP GETDATE. 
 monthToShow: month of the calendar (relative to year ... typically 1 - 12, but 
     can be larger to extend into following year(s))
 yearToShow: year of the calendar (4 digits)
 If either monthToShow or yearToShow are not supplied, then assumes current month in current year.
 firstDayOfWeek: specifies the first day of each displayed week in the calendar, (0 - 6)
     default to Sunday (0)
*/
FUNCTION showCalendar( $monthToShow = NULL  , $yearToShow = NULL , $firstDayOfWeek = 0 ){
 IF (($monthToShow === NULL) OR ($yearToShow === NULL)) {
  $today = GETDATE();
  $monthToShow = $today['mon'];
  $yearToShow = $today['year'];
 }
 ELSE {
  $today = GETDATE(MKTIME(0,0,0,$monthToShow,1,$yearToShow));
 }
 // get first and last days of the month
    $firstDay = GETDATE(MKTIME(0,0,0,$monthToShow,1,$yearToShow));
    $lastDay  = GETDATE(MKTIME(0,0,0,$monthToShow+1,0,$yearToShow)); //trick! day = 0
 
    // Create a table with the necessary header information
    ECHO '<div class = cal><table>';
    ECHO '  <tr><th colspan="7">'.$today['month']."&nbsp;&nbsp;&nbsp;".$today['year']."</th></tr>";
    ECHO '<tr class="days">';
 $dayText = ARRAY ( // this array is used to simplify the display of calendar headers
  // the entries just specify the text to show for the days in the header
  0 => 'Su','Mo','Tu','We','Th','Fr','Sa',
  // duplicate the first 6 entries to simplify display of calendar headers in a loop
  'Su','Mo','Tu','We','Th','Fr'
 );
 FOR ($i=0;$i<7;$i++){ // put 7 days in header, starting at appropriate day ($firstDayOfWeek)
  ECHO '<td>'.$dayText[$firstDayOfWeek + $i].'</td>';
    }
 ECHO '</tr><tr>';
    // Display the first calendar row with correct start of week
 IF ( $firstDayOfWeek <= $firstDay['wday'] ) {
  $blanks = $firstDay['wday'] - $firstDayOfWeek; 
 } 
 ELSE {
  $blanks = $firstDay['wday'] - $firstDayOfWeek + 7; 
 }
 FOR($i=1;$i<=$blanks;$i++){
        ECHO '<td class="noday"> </td>';
    }
    $actday = 0; // used to count and represent each day
 // Note: loop below starts using the residual value of $i from loop above 
    FOR( /* use value of $i resulting from last loop*/ ;$i<=7;$i++){
        ECHO '<td class=hasday>'.++$actday.'</td>';
    }
    ECHO '</tr>';
 
    // Get how many complete weeks are in the actual month
    $fullWeeks = FLOOR(($lastDay['mday']-$actday)/7);
    FOR ($i=0;$i<$fullWeeks;$i++){
  ECHO '<tr>';
        FOR ($j=0;$j<7;$j++){
               ECHO '<td class=hasday>'.++$actday.'</td>';
        }
        ECHO '</tr>';
    }
 
    //Now display the partial last week of the month (if there is one)
    IF ($actday < $lastDay['mday']){
        ECHO '<tr>';
        $actday++;
        FOR ($i=0;$i<7;$i++){
            IF ($actday <= $lastDay['mday']){
                ECHO '<td class=hasday>'.$actday++.'</td>';
            }
            ELSE {
                ECHO '<td class="noday"> </td>';
            }
        }
        ECHO '</tr>';
    }
    ECHO '</table></div>';
}
 
/* demo execution starts here
 This demo example uses showCalendar to package 12 months into 3 rows.
 It defaults to start in the current month.
*/
 $useDefault = TRUE;  // to always start in a particular month, set this false and see (A) below
 IF ($useDefault) { // start at current month
  $thisDay    = GETDATE(); 
  $startMonth = $thisDay['mon'];
  $startYear = $thisDay['year'];
 }
 ELSE {
  $startMonth = 1;   // (A) start at specified month ... January, 2011 in this case
  $startYear = 2011; 
 }
 
 FOR ($block = 1; $block<=3; $block++) { // there are 3 blocks 
  ECHO '<div class = "calblock"><table><tr>';
  FOR ($calcount=1; $calcount <=4; $calcount++) { // each block holds 4 months
   ECHO '<td class = "onecal">';
   showCalendar( $startMonth++,$startYear, 1 /* start all weeks on Monday (1) */);  
   ECHO '</td>';
  }
  ECHO '</tr></table></div>';
 }
?>