Short answer. A court may fix it. Article 1197 says that if the obligation fixes no period but from its nature and circumstances a period was intended, the courts may fix the duration. So the debt is not automatically demandable at once — where a period was clearly meant, the creditor must ask the court to set it first.
What the law says
If the obligation does not fix a period, but from its nature and the circumstances it can be inferred that a period was intended, the courts may fix the duration thereof.
Civil Code, Article 1197 — When the Court Fixes the Period. Read the full provision →
What the law says
The courts shall also fix the duration of the period when it depends upon the will of the debtor.
Civil Code, Article 1197 — When the Court Fixes the Period. Read the full provision →
What the law says
In every case, the courts shall determine such period as may under the circumstances have been probably contemplated by the parties.
Civil Code, Article 1197 — When the Court Fixes the Period. Read the full provision →
What the law says
Once fixed by the courts, the period cannot be changed by them.
Civil Code, Article 1197 — When the Court Fixes the Period. Read the full provision →
The court can set the deadline
Article 1197 handles exactly this gap. It says: If the obligation does not fix a period, but from its nature and the circumstances it can be inferred that a period was intended, the courts may fix the duration thereof. The key is whether a period was intended even though none was written down. If the deal, by its nature, plainly assumed the debtor would have some time to pay — rather than being due the instant it was made — a court can step in and supply the missing deadline. This means the creditor cannot always treat the obligation as payable on the spot; the proper course is to have the period judicially fixed.
When the timing was left to the debtor
The article covers a second situation that often traps creditors. It provides that The courts shall also fix the duration of the period when it depends upon the will of the debtor. If you agreed to pay 'when able' or 'when my means permit', the obligation is not a fiction the creditor can ignore, nor is it something you can postpone forever at whim. The law does not leave payment purely to the debtor's pleasure. Instead, a court sets a definite period — so a promise whose timing was tied to the debtor's will still becomes enforceable within a fixed frame the court determines.
How the court chooses the period
The court does not pick a date arbitrarily. Article 1197 directs that In every case, the courts shall determine such period as may under the circumstances have been probably contemplated by the parties. The judge tries to reconstruct what you and the other side most likely had in mind — the reasonable time the nature of the transaction implies — rather than imposing an outside guess. This keeps the fixed deadline faithful to the bargain you actually struck. It is filling a gap in your agreement with the term you probably meant, not rewriting the agreement into something new.
Once set, it is final
There is a note of finality worth knowing. The article ends: Once fixed by the courts, the period cannot be changed by them. After a court has determined the period, it will not keep revisiting and adjusting the deadline; the matter is settled. So the judicial fixing of a period is a one-time exercise, giving both sides certainty about when payment is due. For a debtor, this is protection against a creditor demanding immediately; for a creditor, it is a route to make an open-ended promise concrete and, once fixed, dependable.