Shiva Purana
निशि यत्नेन कर्तव्यं भोजनं सोमवासरे ॥ उभयोः पक्षयोर्विष्णो सर्वस्मिञ्छिव तत्परैः ॥ १४॥
O Viṣṇu, in both the halves on every Monday, food shall be taken only during the night by the followers of Śiva-cult.
english translation
nizi yatnena kartavyaM bhojanaM somavAsare ॥ ubhayoH pakSayorviSNo sarvasmiJchiva tatparaiH ॥ 14॥
hk transliteration by Sanscript