Chapter 42 mentions several different calendar systems when describing Baba's passing. What are they and how do they align?

Chapter 42 provides a complex and syncretic dating of Sai Baba's Mahasamadhi by aligning multiple calendars. It gives the year as Shaka 1840. From the Hindu solar and lunar calendars, it specifies the event occurred during the sun's southern transit (Dakshinayan) on Vijayadashami in the bright half of the month (Shukla Paksha). This same day is cross-referenced with the Islamic calendar, corresponding to the 9th date of the Muslim month, on the night known as 'Kattal' (the eve of Moharram). The chapter also makes a fine point about the lunar day (tithi), noting that although the day was Dashami, the exact moment of passing at 12:30 PM occurred as the Ekadashi tithi began.