Skandapurana 5.215.88

5.215.88

saṃtṛptā māsamātraṃ ca tasthuḥ saṃtuṣṭamānasāḥ ..
gacchatā tvathakālena dauḥsthyaṃ prāpya narā bhuvi ..
darśe'sminnapi no śrāddhaṃ prāyaḥ kurvaṃti kecana ..88..

Satisfied for only a month, they remained with contented minds. / But as time passed, men on earth fell into misery, / and generally hardly anyone performed the śrāddha even on this new moon day.