If a German supplier delivers late, the customer usually cannot withdraw from the contract at once. He must first set a reasonable further period. Section 323 of the Civil Code makes an exception. No further period is needed if the contract fixed a date or a deadline, and the customer told the supplier before signing that delivery on time was essential to him. The same applies if the circumstances of the deal made the date essential. Lateness alone does not end a German contract. The parties must have made clear in advance that the date itself matters.