Kautilya's Arthashastra 9.1.22

9.1.22

kālaḥ śītoṣṇavarṣātmā //

Time consists of cold, hot, and rainy periods. The divisions of time are: the night, the day, the fortnight, the month, the season, solstices, the year, and the Yuga (cycle of five years). In these divisions of time he should undertake such works as are conducive to the growth of his power and prosperity. That time which is congenial for the manœuvre of his Army, but which is of the reverse nature for his enemy is the best; that which is of the reverse nature is the worst; and that which possesses both the characteristics is of middling quality.