What is mac miller day?

As an AI language model, I cannot provide information on a specific annual celebration called "Mac Miller Day." However, Mac Miller was a rapper and songwriter from the United States. He passed away on September 7, 2018, due to a drug overdose. Fans celebrate his life and music on his birthday, January 19th. Also, the City of Pittsburgh, where Mac Miller was born and raised, declared January 19th "Mac Miller Day" in his honor. Fans often pay tribute to the late artist on this day by sharing his music and remembering his impact on the music industry.