code: def locked?
        return false if lockouttime.zero?
        epoch = 116_444_736_000_000_000
        current = Time.now.to_i * 10_000_000
        current - (lockouttime - epoch) < lockoutduration
      end
docs: https://fossies.org/linux/web2ldap/pylib/w2lapp/schema/plugins/activedirectory.py
   https://msdn.microsoft.com/en-us/library/windows/desktop/ms676843(v=vs.85).aspx