You don’t? If you leave it in the fridge you just have rock hard butter.

It mostly only matters if there is buttercream frosting on top, which can melt easily if it gets warm. Cheesecake by itself is fairly durable.

Butter does well for a while but will eventually go rancid, though most sticks don’t last long enough for it.

Sour cream, cracked eggs, and cream cheese, however, are t known for their longevity outside the fridge.