Mahabharata 5.140.18

सप्तमाच्चापि दिवसादमावास्या भविष्यतिसंग्रामं योजयेत्तत्र तां ह्याहुः शक्रदेवताम्

saptamāccāpi divasādamāvāsyā bhaviṣyatisaṃgrāmaṃ yojayettatra tāṃ hyāhuḥ śakradevatām

Our plain-language meaning of this verse is waiting for scholar review.