Artículo 22. IAS 21 Paragraph 22

The date of a transaction is the date on which the transaction first qualifies for recognition in accordance with IFRSs. [ Note: IFRIC 22 addresses the exchange rate to use in transactions in which an entity has received advance consideration in a foreign currency] For practical reasons, a rate that approximates the actual rate at the date of the transaction is often used, for example, an average rate for a week or a month might be used for all transactions in each foreign currency occurring during that period. However, if exchange rates fluctuate significantly, the use of the average rate for a period is inappropriate.