According to the second paragraph of Article 117/11 of the Turkish Code of Obligations (TCO), where a date for performance of the obligation has been set by an agreement, the obligor is automatically in default as of this date. However, the parties sometimes may have agreed that the obligation will be due upon a definite period of time after occurrence of an event that is expected in the future. According to the classical view in doctrine, in order to be able to accept a definite maturity (tempus certum), in the contract, the due date must be determined as a fixed date or a date which is precisely foreseeable as a calendar day at the time of the conclusion of the contract. Otherwise, in order for the debtor to fall into default, the creditor must give notice for performance. However, according to the second view in the doctrine, if the due date becomes definite or definable at a date after the conclusion of the contract and before the time of performance, then the maturity of the debt also becomes definite and therefore no notice for performance is required. This is the case, for example, if the contract states, when payment is to be made within ten days of the delivery of the goods. The Turkish Court of Cassation gives contradictory decisions, but often its decisions are grounded in the classical view. On the other hand, if the expected future event in the contract is not realized, it is necessary to evaluate how the due date will be calculated and whether a notice for performance is required.