Chapter 42 mentions that the day of Baba's passing was also significant for other reasons. What were they?

Yes, Chapter 42 highlights the multifaceted significance of the day Sai Baba left his body. The primary significance for Hindus was that it was Vijayadashami (Dussehra), a major festival. The text also notes that for some people, that particular day was observed as Buddha Jayanti. Furthermore, it held significance in the Islamic calendar, as it was the 9th day of the month, which is the eve of Moharram, referred to in the text as the night of 'Kattal'. Chapter 42 uses this convergence to make a profound point: while people celebrate the birth anniversaries of gods, for saints like Sai, it is their death anniversary (Punya Tithi) that becomes a sacred and memorable occasion for devotees.