$regex = '/.*bKd{4}-d{2}-d{2}/s';
preg_match_all($regex, $entry_raw, $date, PREG_SET_ORDER, 0);

$date = $date[0][0];

// TRIM 'BODY' DOWN TO FIRST PARAGRAPH
$entry = explode("n", $entry_raw);

// CONNECT TO DATABASE
$hostname = "xxx";
$database = "xxx";
$username = "xxx";
$password = "xxx";

$con = mysqli_connect($hostname, $username, $password, $database) or die (mysql_error());

if ($con->connect_error) {
    die("ERROR: Unable to connect: " . $con->connect_error);
}

$stmt = $con->prepare("SELECT id FROM users WHERE email=?");
$stmt->bind_param("s", $from[1]);
$stmt->execute();
$stmt->bind_result($id);
$stmt->fetch();
$stmt->close();

if ($id) {
    $stmt = $con->prepare("INSERT INTO entries (entry, user_id, date) VALUES (?, ?, ?)");
    $stmt->bind_param("sis", $entry[0], $id, $date);
    $stmt->execute();
    $stmt->close();
}

$entry_raw = "this is some text 1111-11-11 2222-22-22 this is some more text";
$regex = '/.*bKd{4}-d{2}-d{2}/s';
preg_match_all($regex, $entry_raw, $date, PREG_SET_ORDER, 0);
$date = $date[0][0];
echo $date;