If a debt or any obligation to one of the parties must be fulfilled at the end of a certain period starting from the establishment of the contract, the time of execution is determined as follows: 1. The period set as a day shall expire on the last day of this period, not counting the day on which the contract is established. If it is a period set as eight or fifteen days, it refers to the full eight or fifteen days, not one or two weeks. 2. The period set as a week expires on the day of the last week that matches the date of the contract’s establishment by name. 3. A period determined as a month or as a time containing multiple months, such as a year, semester, and quarter of the year, expires on the day of the last month that corresponds to it, if the date of the contract is the second day of the month. If there are no days in the last month that meet this, the period is considered to have expired on the last day of this month. 4. Fifteen days from half a month is clear. The day on which the period set as one or more months and half months expires is determined by adding fifteen days to the last month. These rules also apply in cases where the period begins to process from another moment of the establishment of the contract. The borrower is obliged to fulfill a debt that must be fulfilled within a certain period of time before the expiration of this period.