get.first.day.of.week.php

<?php

/* input the year and week you want, then get the date! */
function getFirstDayOfWeek($year, $weeknr, $date_format="Y-m-d"){
    $offset = date('w', mktime(0,0,0,1,1,$year));
    $offset = ($offset < 5) ? 1-$offset : 8-$offset;
    $monday = mktime(0,0,0,1,1+$offset,$year);
    $date = strtotime('+' . ($weeknr - 1) . ' weeks', $monday);
    return date($date_format,$date);
}

/* test. check the calendar:) */
echo getFirstDayOfWeek(2010,11),"\n";
echo getFirstDayOfWeek(2010,45),"\n";
echo getFirstDayOfWeek(2011,1),"\n";
echo getFirstDayOfWeek(2011,6),"\n";

?>