saber numero de semana y crear semana

[FNX_NET]

gracias, solo le pege esta enchulada

echo $semana=strftime("%W");
//Con la semana obtendremos la timestamp correspondiente y la fecha del primer dia:
$ano=date ("Y")-1970;
for($int = 0 ; $int<55;$int++)
{
echo "<br>";
$timestamp=(($int)*7+$ano*365+ceil($ano/4))*24*3600;
// $primerdia=date ("d/m/Y",$timestamp);
echo $primerdia=date ("d",$timestamp);
echo " ";
echo $segundodia=date ("d",($timestamp+1*24*3600));
echo " ";
echo $tercerodia=date ("d",($timestamp+2*24*3600));
echo " ";
echo $cuartodia=date ("d",($timestamp+3*24*3600));
echo " ";
echo $quintodia=date ("d",($timestamp+4*24*3600));
echo " ";
echo $septodia=date ("d",($timestamp+5*24*3600));
echo " ";
echo $sextodia=date ("d",($timestamp+6*24*3600));
echo "";
}
?>