“When they had sung many songs, and talked of many things they had done together, they toasted Bilbo’s birthday, and they drank his health and Frodo’s together according to Frodo’s custom.” ― The Fellowship of the Ring, Three is Company.
After Bilbo Baggins left Bag End after his 111th birthday, Frodo Baggins gave a toast to his uncle on Bilbo and his uncle’s birthday. (They both shared the same birth date.) Samwise Gamgee carried on the tradition after Frodo and Bilbo made the trip to the Undying Lands. I would like to think that Frodo Gardner (the oldest son of Samwise and his wife Rose Cotton) continued the celebration as well.