Hey,
So recently I wanted to check my friends to see if any of them had their birthday for the current day. Using FQL this is super easy and I encourage you to explore FQL more because it will yield a more efficient solution than, say, what Pierre kindly offered. Here is a small snippet of the code:
$friends = $facebook->api_client->friends_get();
$uids = "";
foreach($friends as $f) {
$uids .= "uid=$f OR ";
}
$query_uids = substr($uids,0,strlen($query_uids)-4);
date_default_timezone_set('UTC');
$current_date = date("m/d");
echo "<br />Searching for birthdays for the given month/day: $current_date<br />";
$data = $facebook->api_client->fql_query( "SELECT name, uid FROM user WHERE ( ($query_uids) AND strpos(birthday_date,'$current_date') >= 0 )" );
if(count($data) > 0) {
foreach($data as $d) {
print_r($d);
}
} else {
echo "<br />No Birthdays Today<br />";
}