Musannaf Ibn Abi Shayba 33:973

Yazid ibn Harun narrated to us, he said: Mubarak informed us, from al-Hasan, who said: By Allah, they are not the worst days for the believer; they are days in which his term is brought closer to him, and he remembers what he had forgotten of his return [to Allah], and his sins are expiated by them.