Arthashastra
दिवस पञ्च रात्र पक्ष मास चातुर्मास्य संवत्सरैश् च प्रतिसमानयेत् ॥
It shall also be verified with reference to (such divisions of time as) days, five nights, pakshás, months, four-months, and the year.
english translation
divasa paJca rAtra pakSa mAsa cAturmAsya saMvatsaraiz ca pratisamAnayet ॥
hk transliteration by Sanscript