why doesn't my ac work in the afternoon?

many power company's have an interrupt installed. a signal is sent on the power line and shuts off those on interrupt service durring times of peak demend for a while. It will be a grey box with small lights that show through a clear opening in the cover. it will shut off the condenser unit but the blower on the furnace will continue to run.and it will not effect any other electrical functions in the home.

If the outside temperature is falling below what you want your inside temperature to be (77 in your case), then you need to put a fan cycle switch on your outside a/c unit. Based on the information you've given, that's the only thing I can think of that's causing the problem.

backflush your condenser coils clean them with high pressure nozzle from the inside out when you take that york apart to clean take the plastic mesh thats around the coils and throw it away

You may have supernatural entities that are creating a heat source. Worst case scenario, it could be a demon but it's likely a poltergeist.