aca lo resolvi
saludos
Código PHP:
<?php
setlocale(LC_TIME,"es_CL");
$sunday_val = 0;
$saturday_val = 6;
$seconds_per_day = 86400;
$d_weekend_days = 0;
$p_start_date = "2009-01-01";
$p_end_date = "2009-12-31";
$start_date = strtotime($p_start_date);
$end_date = strtotime($p_end_date);
for($day_val = $start_date; $day_val <= $end_date; $day_val += $seconds_per_day){
$pointer_day = date("w", $day_val);
if(($pointer_day == $sunday_val) || ($pointer_day == $saturday_val)){
echo date("d/m/Y",$day_val)."<br>";
$d_weekend_days++;
}
}
?>