Kautilya: Arthashastra(ca. 400 BCE–300 CE)
Book 1: Concerning Discipline
Chapter XIX: The Duties of a King
If a king is energetic, his subjects will be equally energetic. If he is reckless, they will not only be reckless likewise, but also eat into his works. Besides, a reckless king will easily fall into the hands of his enemies. Hence the king shall ever be wakeful.
He shall divide both the day and the night into eight nálikas (1½ hours), or according to the length of the shadow (cast by a gnomon standing in the sun): the shadow of three purushás (36 angulás or inches), of one purushá (12 inches), of four angulás (4 inches), and absence of shadow denoting midday are the four one-eighth divisions of the forenoon; like divisions (in the reverse order) in the afternoon.
Of these divisions, during the first one-eighth part of the day, he shall post watchmen and attend to the accounts of receipts and expenditure; during the second part, he shall look to the affairs of both citizens and country people;...
R. Shamasastry, trans. Arthashastra. Bangalore: Government Press, 1915.