Yuga-Vibhāga and Kāla-Pramāṇa
Measures of Time and the Four Yugas
काष्ठा निमेषा दश पञ्च चैव त्रिशच्च काष्ठा गणयेत्कलां तु / त्रिंशत्कलाश्चापि भवेन्मुहूर्त्तस्तै स्त्रिंशता रात्र्यहनी समे ते
kāṣṭhā nimeṣā daśa pañca caiva triśacca kāṣṭhā gaṇayetkalāṃ tu / triṃśatkalāścāpi bhavenmuhūrttastai striṃśatā rātryahanī same te
Fifteen nimeṣas make one kāṣṭhā; thirty kāṣṭhās are reckoned as one kalā; thirty kalās make one muhūrta; and by thirty muhūrtas, night and day are formed in equal measure.