What I am certain is that these deaths bring in Pitru Dosha and Pariharas are necessary.
The Days inauspicious for Death fall under three categories.
Relating to the Nakshatras, Stars.
Rohini, Dhanishta, Satabhisham, Purvabhadra, Revathi, Mrugasira, Punarvasu, Uttara, Chitra, Visakha, Uttarashada, and Magha.
Thithis, Waxing and Waning of the Moon.
Padyami, Vidiya, Shashti, Ashtami, Ekadasi, Dwadasi, Trayodasi, Chaturdasi and Amavasya.