public function get_start() {
        if (!empty($this->start)) {
            return $this->start;
        }

        // Much faster than reading the first log in the site.
        $admins = get_admins();
        $this->start = 9999999999;
        foreach ($admins as $admin) {
            if ($admin->firstaccess < $this->start) {
                $this->start = $admin->firstaccess;
            }
        }
        return $this->start;
    }