1. If a condition is fulfilled, its effect shall be retroactive to the time at which the obligation arose, unless it is apparent from the will of the contracting parties or from the nature of the contract that the existence or extinction of the obligation is to take effect only at the time the condition is fulfilled. 2. A condition shall not have a retroactive effect if the performance of the obligation before the fulfillment of the condition was impossible for a reason beyond the debtor’s control.
Interpretation and application must be checked against the official text and current version.