birthday.php

<?php

/**
 * @param DateTime        $dob
 * @param string|DateTime $end
 *
 * @return DatePeriod
 */
function getBirthdays(DateTime $dob, $end = 'today 23:59:59')
{
    if (!$end instanceof DateTime) {
        $end = new DateTime($end);
    }

    return new DatePeriod($dob, new DateInterval('P1Y'), $end);
}

/**
 * @param DateTime        $dob
 * @param string|DateTime $end
 *
 * @return mixed
 */
function getLastBirthday(DateTime $dob, $end = 'today 23:59:59')
{
    /** @var DateTime[] $birthdays */
    $birthdays = iterator_to_array(getBirthdays($dob, $end));

    return array_pop($birthdays);
}

$last_week = new DateTime('-7 days 00:00');
if (!empty($cur_user['last_showed'])) {
  $last_showed = new DateTime($cur_user['last_showed']);
} else {
  $last_showed = new DateTime('1970-01-01');
}
$last_birthday = getLastBirthday(new DateTime($cur_user['dob']));

$had_birthday = $last_birthday > $last_week;
$show_movie = $last_showed < $last_week;