<?php

$week_day = date("w");

$weekend = 6; // sabado

// Verifica quantos dias faltam para o fim de semana (sabado) proximo
$diff = $weekend - $week_day;

// Obtem dia do proximo sabado
$weekend_day['saturday'] = date("d/m/Y", mktime(0, 0, 0, date("m"), (date("d") + $diff), date("Y") ));
$weekend_day['sunday'] = date("d/m/Y", mktime(0, 0, 0, date("m"), (date("d") + $diff + 1), date("Y") ));

echo "Fim de semana da semana:<br />";
echo "S�bado: ".$weekend_day['saturday'];
echo "<br />";
echo "Domingo: ".$weekend_day['sunday'];

?>