How did the Ram Navami festival become a permanent annual celebration in Shirdi?

The establishment of the annual Ram Navami festival in Shirdi was a direct result of a prayer made by Dasganu. While the text in Chapter 6 describes a particularly successful Ram Navami celebration performed by Balabuva Satarkar, it was a subsequent event that made it a permanent fixture. After Balabuva's visit, another devotee, Dasganu, came to Shirdi. He prayed to Sai Baba and successfully 'had the annual festival established for them.' From that point forward, as the source mentions, the birth festival was celebrated every year with great pomp and circumstance, including a feast for all, ensuring the tradition continued.