WHAT ARE THE 96 (SHANNAVATI) PITRU TARPANAS?

The 96 (shannavati) pitru tarpaNas to be performed in a year are :
1. amavAsya -- 12
2. yugAdi -- 4
3. manvAdi -- 14
4. Masa tarpaNam -- 12
5. vaiDhruti -- 13
6. vyatIpAtam -- 13
7. mahAlayam -- 16
8. ashtakA -- 4
9. anvashtakA -- 4
10.tisroshtakA -- 4