Can Pind Daan be performed for ancestors whose death date is not known?

Yes. If the exact date of passing is not known, Pind Daan can be performed during Sarva Pitru Amavasya (the final day of Pitrupaksha) which is dedicated to all ancestors regardless of when or how they died. This is sometimes called the universal Pind Daan day. Our Pandits will incorporate appropriate mantras in the Sankalpa to cover ancestors whose tithis are unknown. Simply inform us of this situation at the time of booking.