Skandapurana 6.3.51.7

6.3.51.7

manvantarādayaścaite anantaphaladāḥ smṛtāḥ .
ayane cottare rājandakṣiṇe śrāddhamācaret .. 51.7 ..

These beginnings of the manvantaras are remembered as yielding endless fruit. / And at the northern solstice, O king, and at the southern, one should perform a śrāddha;