Need help with print monthly calendar function

[duckduckgoose]

I'm trying to print out a monthly calendar, but it's only printing out 6 days and not even accurately... I've been through a number of times, but I think I'm just flatout not seeing something... Here's the code:

function last_day($month, $year) {
  return mktime(23, 59, 59, $month + 1, 0, $year);
}

function print_calendar($month, $year, $weekdaytostart = 0) {
  global $session, $database;

  $last = idate('d', last_day($month, $year));

  $opts = '<a href="'.$_SERVER['PHP_SELF'].'?month=%d&year=%d&amp;view=2">%s</a>';
  list($prev_month, $prev_year) = split(',',strftime('%m,%Y',mktime(0,0,0,$month-1,1,$year)));
  $prev_month_link = sprintf($opts, $prev_month, $prev_year, '&laquo;');

  list($next_month, $next_year) = split(',',strftime('%m,%Y',mktime(0,0,0,$month+1,1,$year)));
  $next_month_link = sprintf($opts, $next_month, $next_year, '&raquo;');

  $firstdaystamp = mktime(0,0,0, $month, 1, $year);
  $firstwday = idate('w', $firstdaystamp);
  $name = date('F', $firstdaystamp);


  $weekorder = array();
  for ($wo = $weekdaytostart; $wo < $weekdaytostart + 7; $wo++) {
    $weekorder[] = $wo % 7;
  }

  $calendar = '<div id="calendar-header-left">'.$prev_month_link.'</div><div id="calendar-header">'.$name.' '.$year.'</div><div id="calendar-header-right">'.$next_month_link.'</div>';

  foreach ($weekorder as $w) {
    $dayname = date('D', mktime(0,0,0, $month, 1 - $firstwday + $w, $year));
    $calendar .= '<div class="calendar-weekdays">'.$dayname.'</div>';

  }
  $calendar .= '<div style="clear:both"></div>';
  $onday = 0;
  $started = false;

  while($onday <= $last) {

foreach($weekorder as $d) {
  if(!($started)) {
    if($d == $firstwday) {
      $started = true;
      $onday++;
    } /* ends firstwday */
  } /* ends if started */

  if(($onday == 0) || ($onday > $last)) {
    $calendar .= '<div class="calendar-day-blank">
					<div class="calendar-day-date">&nbsp;</div>
					<div class="calendar-day-text">&nbsp;</div>
				  </div>';
  } else {
    $calendar .= '<div class="calendar-day">
					<div class="calendar-day-date">'.$onday.'</div>
					<div class="calendar-day-text">&nbsp;</div>
				  </div>';
    $onday++;
  }
} /* ends else statement */
  } /* ends foreach weekorder as d */

  return $calendar;
}