From which day it is counted
Under article 150 of the Civil Code, the general limitation period is three years. Under article 154, it starts on the day the person learned or should have learned of the breach of the right. Under a contract it usually starts on the day the period for performance ends.
An important point
The court does not apply the limitation period on its own initiative. Under article 153 of the Civil Code, it applies only on the application of a party to the dispute, made before the court renders the judgment. So you may file a claim even after the period expired. But if the party makes such an application and the period expired, the court rejects the claim.
Suspension and interruption
The law suspends or interrupts the period in the cases it names. For example, under article 157 of the Civil Code, an act of the debtor that shows the debtor acknowledges the debt interrupts the period, and the period starts again.
Advice
Keep the written document in which the debtor acknowledges the debt (a letter, a reconciliation act, a payment). It renews the period.