Eagle, it varies from person to person.
I was up and walking a little bit about 9 hours after surgery ended....then two or three times the next day, then released to go home after the second night.
Tried to walk for 10-15 minutes every couple of hours when I got home....sometimes in the back yard...sometimes on the street.
I went to lunch and dinner, with my trusty catheter along for the fun, several times. It helped me emotionally to get out of the house and see my friends.
I found a recliner to be comfortable when I was sitting. Even slept in one a few times.
Encourage your dad to do what he can to be active, but without overdoing it.