Days

1. By adoring the Pitris on the first day of the lighted fortnight, one obtains in one's abode beautiful spouses capable of producing many children all possessed of desirable accomplishments. 
2. By performing the Sraddha on the second day of the lighted fortnight one gets many daughters. 
3. By performing it on the third day, one acquires many steeds. 
4. By performing it on the fourth day, one gets a large herd of smaller animals (such as goats and sheep) in one's house. 
5. They, O king, who perform the Sraddha on the fifth day, get many sons. 
6. Those men who perform the Sraddha on the sixth day acquire great splendour. 
7. By performing it on the seventh day, O monarch, one acquires great fame. 
8. By performing it on the eighth day one makes great profits in trade. 
9. By performing it on the ninth day one acquires many animals of uncloven hoofs. 
10. By performing it on the tenth day one acquires much wealth in kine. 
11. By performing it on the eleventh day one becomes the possessor of much wealth in clothes and utensils (of brass and other metals). Such a man also obtains many sons all of whom become endued with Brahma splendour. 
12. By performing the Sraddha on the twelfth day one always beholds, if one desires, diverse kinds of beautiful articles made of silver and gold. 
13. By performing the Sraddha on the thirteenth day one attains to eminence over one's kinsmen. 
14. Without doubt, all the young men in the family of him who performs the Sraddha on the fourteenth day meet with death. Such a man becomes entangled in war, 

By performing the Sraddha on the day of the new moon, one obtains the fruition of every wish. In the dark fortnight, all the days commencing with the tenth (and ending with that of the new moon), leaving only the fourteenth day out, are laudable days for the performance of the Sraddha. Other days of that fortnight are not so. Then, again, as the dark fortnight is better than the lighted one, so the afternoon of the day is better than the forenoon in the matter of the Sraddha.'"

http://www.sacred-texts.com/hin/m13/m13b052.htm
https://www.drikpanchang.com/vrats/shraddhadates.html