Find the dates of a repeating event

gistfile1.aw

<?php

/**
 * Find dates of repeating events between two dates
 */
function find_recurring_dates($start_date, $end_date, $repeat_days){
  $start = new DateTime($start_date);
  $end = new DateTime($end_date);
    
  // Find the number of days inbetween
  $interval = $start->diff($end);
  $num_days = $interval->days;

  $return = array();
  // Loop through all days in between start and end dates (inclusive)
  for ($i = 0; $i <= $num_days; $i++) {
    // Get date from start date plus loop increment
    $incremented_date = strtotime('+' . $i . 'days', strtotime($start_date));
    
    // Numeric representation of the day of the week -- 0 (for Sunday) through 6 (for Saturday)
    $date = date('w', $incremented_date);
      
    // Check to see if its in the repeat days array
    if (in_array($date, $repeat_days)) {
      $return[] = date('Y-m-d', $incremented_date);
    }
  }

  return $return;
}

/**
Input:
  $start_date  = '2012-03-02';
  $end_date    = '2012-03-31';
  $repeat_days = array(1,3,5); // Mon/Wed/Fri

Output:
  Array
  (
    [0] => 2012-03-02
    [1] => 2012-03-05
    [2] => 2012-03-07
    [3] => 2012-03-09
    [4] => 2012-03-12
    [5] => 2012-03-14
    [6] => 2012-03-16
    [7] => 2012-03-19
    [8] => 2012-03-21
    [9] => 2012-03-23
    [10] => 2012-03-26
    [11] => 2012-03-28
    [12] => 2012-03-30
  )
*/

?>