Quote from JoshuaThis was because he did not desire any birthday sacrifice or feast; yet he himself sacrificed on the traditional birthdays of Plato and of Socrates, afterwards giving a banquet at which every member of the circle who was able was expected to deliver an address.
--Porphyry, De Vita Plotini
So apparently feasting and sacrifices were part of birthday celebrations for Plato and Socrates. Does this make them cultish? If it makes the Epicureans cultish, they're not alone.
Great cite Joshua !