With regard to what Moses records, that Pharaoh celebrated his birthday by a great feast, we know that this custom has always been in use, not only among kings, but also among plebeian men. Nor is the custom to be condemned, if only men would keep the right end in view; namely, that of giving thanks unto God by whom they were created and brought up, and whom they have found, in innumerable ways, to be a beneficent Father. But such is the depravity of the world, that it greatly distorts those things which formerly were honestly instituted by their fathers, into contrary corruptions. Thus, by a vicious practice, it has become common for nearly all to abandon themselves to luxury and wantonness on their birthday. In short, they keep up the memory of God, as the Author of their life, in such a manner as if it were their set purpose to forget Him.
– John Calvin, Commentary on Genesis 40:19