How Long Can A Catheter Be Worn?

How long is it safe to leave a catheter in a man. My husband is 71 years old and could not void last Sat night. Called urologist which sent us to the ER. They catherized him and. Left it in and told him to be at Dr office 9 am Monday. We did and a PA saw him and said to leave in until Sunday and for ME to remove it and come back Monday week. The Cath will have been in 8 days by then.. it is a very large tube and VERY painful for him.