My chickens are dying every tuesday at exactly noon. Why are they dying?

I just moved into a new house and It came with a chicken coup. At first I thought it would be fun to have chickens until the first one died. I thought it had died normally until the next one died and then the next one after that. This might sound normal, but I'm taking excellent care of them and they are all dying on Tuesday at exactly noon! I really just don't understand why they are dying and I'm starting to think there might be ghosts involved. What do I do?