[Update] Per the Davis Cup site today (6 Mar), they hope to be able to start repairs on the stadium in the afternoon (local time). Continuing high winds were preventing work on the stands in the morning.
Davis Cup rules allow for play on up to five days, so play on Monday or even Tuesday is theoretically possible. The rules also allow for a certain amount of flexibility of scheduling, so three matches on Saturday or Sunday are possible, although with Novak Djokovic due to play in three matches and daylight only until just after six o’clock in the evening, it seems unlikely that this will happen.
According to SportsYa, day one of the tie has been suspended due to high winds.
According to Pedro Hernandez, press chief at the Spanish Tennis Federation (RFET), the main umpire at the competition decided to cancel Friday opener at the Davis Cup in order to see whether the workers can repair the damage on the grandstands.
“Due to the weather conditions affecting the whole country, which affected the grandstands at the stadium, we decided to suspend Friday round,” he said.