<?php
function build_calendar($month,$year) {
  // Create array containing abbreviations of days of week.
  $daysOfWeek = array('S','M','T','W','T','F','S');
  // What is the first day of the month in question?
  $firstDayOfMonth = mktime(0,0,0,$month,1,$year);
  // How many days does this month contain?
  $numberDays = date('t',$firstDayOfMonth);
  // Retrieve some information about the first day of the
  // month in question.
  $dateComponents = getdate($firstDayOfMonth);
  // What is the name of the month in question?
  $monthName = $dateComponents['month'];
  // What is the index value (0-6) of the first day of the
  // month in question.
  $dayOfWeek = $dateComponents['wday'];
  // Create the table tag opener and day headers
  $calendar = "<table class='calendar'>";
  $calendar .= "<caption>$monthName $year</caption>";
  $calendar .= "<tr>";
  // Create the calendar headers
  foreach($daysOfWeek as $day) {
     $calendar .= "<th class='header'>$day</th>";
  }
  // Create the rest of the calendar
  // Initiate the day counter, starting with the 1st.
  $currentDay = 1;
  $calendar .= "</tr><tr>";
  // The variable $dayOfWeek is used to
  // ensure that the calendar
  // display consists of exactly 7 columns.
  if ($dayOfWeek > 0) {
     $calendar .= "<td colspan='$dayOfWeek'> </td>";
  }
  $month = str_pad($month, 2, "0", STR_PAD_LEFT);
  while ($currentDay <= $numberDays) {
     // Seventh column (Saturday) reached. Start a new row.
     if ($dayOfWeek == 7) {
       $dayOfWeek = 0;
       $calendar .= "</tr><tr>";
     }
     $currentDayRel = str_pad($currentDay, 2, "0", STR_PAD_LEFT);
     $date = "$year-$month-$currentDayRel";
     $calendar .= "<td class='day' rel='$date'>$currentDay</td>";
     // Increment counters
     $currentDay++;
     $dayOfWeek++;
  }
  // Complete the row of the last week in month, if necessary
  if ($dayOfWeek != 7) {
     $remainingDays = 7 - $dayOfWeek;
     $calendar .= "<td colspan='$remainingDays'> </td>";
  }
  $calendar .= "</tr>";
  $calendar .= "</table>";
  return $calendar;
}
//调用方法
echo build_calendar(05,2016);
?>