Maricismriti 1.9: Kālanirṇaya (Kālamādhavīya) · Nirṇayasindhu · Saṃvatsaradīdhiti +2

1.9

pratimāsaṃ mṛtāhe yat śrāddhaṃ ca prativatsaram | manvādau ca yugādau ca māsayor ubhayor api

The śrāddha which [is performed] every month on the day of death, and every year, / and at the beginning of a manvantara and at the beginning of a yuga, and also in both months—

The monthly śrāddha on the day of death, the annual one, and those on the beginnings of the Manu-ages and of the yugas, (are to be done) in both months (when there is an intercalary month).