Duties would include: shopping, laundry, cleaning, taking them to doctors appointments and other family and social events, providing meals (mostly dinner) each day, and helping with other various needs as they may arise. My dad is in very good health for someone the age of 90 and takes no medications. He is currently able dress, go to the bathroom on his own and take showers, but he does need assistance with someone putting out clean clothes, helping with hearing aides, and giving him general instructions each day to keep him going in the right direction as he gets confused from time to time. He also suffers from Sundowners at night and gets more confused and disoriented, so he needs to be more supervised in the evening than he does during the day.
My main concern is that your Dad has sundowners which means his caregiver would be working 2 shifts each day. And possible part of a 3rd shift thus limited time to sleep. Unfortunately, that caregiver will crash and burn in a short time.
My Dad had around the clock caregivers, 3 separate shifts, each a different person and he found that was extremely expensive. Thus, it was less expensive for Dad to go into Independent Living with his sundowning, but eventually he needed to transfer over to the facilities Assisted Living/Memory Care as his sundowning was getting worse :( He was trying to go outside at night. Dad really loved where he was living, being around people of his own generation :)