All of this presumes that the milk is free of pathogenic bacteria and that spoilage is your only concern. When we produced our own milk  the morning milking was separated for cream for making butter and the skim fed to the animals. The evening milking was saved for the next day's consumption, any left over milk went out to the animals the next morning.

Our cows were vet tested each year for diseases that could infect humans. Sometimes in the spring mother would make cottage cheese with some of the surplus milk but two day old milk was treated like two day old bread— if that was all we had we used it but fresh was always better.