Real Madrid and Real Socieded will play the final six minutes of their match, which was abandoned on Sunday because of a bomb scare.
Spectators were evacuated with the score at 1-1 and two minutes of normal time remaining in the game.
The teams will now play the final two minutes, plus four minutes of injury time, on 5 January.
Brazilian Ronaldo and England captain David Beckham had to wait in the street in their kit after the abandonment.
Real Sociedad president Jose Luis Astiazaran said: “We thought the best thing was to play the time remaining.”
The two clubs met the Spanish FA on Monday and Astiazaran added: “We thought about giving the game as concluded but after talking with the FA we decided there was no precedent for that and the best thing was to play the time that was remaining.”