How long does DT from alcohol withdrawal last?

A relative is in the hospital for minor surgery after an accident but now has severe symptoms from alcohol withdrawal. He had to be restrained because he thought he was being held hostage and tried to call the police to get him out of the hospital. They started giving him a sedative and postponed the surgery but he is still very confused and belligerent and yelling at everyone. How long does it take for this to pass? I guess he didn’t tell anyone at the hospital about how much he typically drinks and his wife didn’t volunteer the information either so he was in the hospital for over 24 hours before this started and they began to sedate him.