Novak Djokovic 's birth month is May .
Novak Djokovic , Новак Ђоковић , Novak Đoković ; born June 22 , 1987 , often referred to by the hypocorism Nole , is a Serbian professional tennis player who is currently ranked world No . 2 in men 's singles tennis by the Association of Tennis Professionals .
Novak Djokovic