A/C not blowing cold during mid day

This is pretty typical of a system that is low on Freon. We need to start with getting the pressure of the high and low side. This will tell us if there is enough Freon in the system. If not then we need to pull it down into in a vacuum and make sure it can hold a vacuum because if it has a leak then if you add Freon, it will just leak out again. This is not good because you have R12 which is the old style refrigerant and this is very expensive these days.

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

If you do not have a gauge set, you can rent them from most parts stores. Let me know what you find and we can go from there.