Madpad is a new type of holiday - in fact, two holidays. One when you reach the exact age your mother was born (MAD), and the other the exact age your father was born (PAD). Each year after that, you have MAD1, PAD1, MAD2, etc for ever! Two more reasons to eat cake. However its hard to calculate, so here you go.
Not 100% on the calculation! Test it by hand