आषाढशुक्लपक्षे तु शयानं च जनार्दनम्।
दृष्ट्वा यः पूजयेन्नित्यं स याति परमां गतिम्॥

“He who worships Janārdana on the bright fortnight of Āṣāḍha when He reclines (enters sleep), attains the supreme abode.”

Vishnu in yoganidra during chaturmasa (period of rains). Generally observed as chaturmasa deeksha when all the sadhus stop travel. No major festivals and gatherings are held. People stay home and flip their gaze inwards though meditation and self reflection. Perhaps a response to monsoons and a period where one can catch infections and fall sick very easily.

कार्तिके शुक्लपक्षे तु प्रबोधं च जनार्दनम्।
दृष्ट्वा यः पूजयेन्नित्यं स मुक्तो नात्र संशयः॥

“In the bright fortnight of Kārtika, when Janārdana awakens, one who worships Him becomes liberated — there is no doubt.”