People in the prime of life can first serve others, having these hours credited to their accounts at the service bank, and then later when they need service them-selves they can go to the bank and make a withdrawal.
人們可以在年富力強的時候先服務別人，將服務時數儲存在銀行裡，日後老了一旦需要服務，便可以向銀行提領。