Article 1187

The effects of a conditional obligation to give, once the condition has been fulfilled, shall retroact to the day of the constitution of the obligation. Nevertheless, when the obligation imposes reciprocal prestations upon the parties, the fruits and interests during the pendency of the condition shall be deemed to have been mutually compensated. If the obligation is unilateral, the debtor shall appropriate the fruits and interests received, unless from the nature and circumstances of the obligation it should be inferred that the intention of the person constituting the same was different.

In obligations to do and not to do, the courts shall determine, in each case, the retroactive effect of the condition that has been complied with. (1120)