<?php
function getMondays($year) {
  $newyear = $year;
  $week = 0;
  $day = 0;
  $mo = 1;
  $mondays = array();
  $i = 1;
  while ($week != 1) {
   $day++;
   $week = date("w", mktime(0, 0, 0, $mo,$day, $year));
  }
  array_push($mondays,date("r", mktime(0, 0, 0, $mo,$day, $year)));
  while ($newyear == $year) {
   $test =  strtotime(date("r", mktime(0, 0, 0, $mo,$day, $year)) . "+" . $i . " week");
   $i++;
   if ($year == date("Y",$test)) {
     array_push($mondays,date("r", $test));
   }
   $newyear = date("Y",$test);
  }
  return $mondays;
}
echo '<pre>';
print_r(getMondays('2006'));
echo '</pre>';
?>