When did the regular Chavadi celebrations begin, and how was the event initiated?

The tradition of Sai Baba sleeping at the Chavadi on alternate nights continued until His Samadhi. However, Chapter 37 specifies that the formal worship, bhajan, and adoration as part of the Chavadi celebration began on December 10th, 1910. The event would commence with the bhajan group arriving at the Masjid to sing. The author notes that the 'enthusiasm of grace' for the celebration was provided by Sai Himself, who, like a powerful magnet, would attract the 'iron-like devotees' and draw them unknowingly to His feet for the grand procession.