Matsyapurana 142.4

142.4

kāṣṭhā nimeṣā daśa pañca caiva triṃśacca kāṣṭhāṃ gaṇayetkalāṃ tu
triṃśatkalāścaiva bhavenmuhūrtas taistriṃśatā rātryahanī samete //

Sûta said:—Although I narrated about them in course of my description of the earth and celestial firmament I shall still tell you something more in detail about them I shall first state about measurements Human years are determined by ordinary experience of men And this is the unit The measurements of the four yugas will be expressed on this unit Fifteen twinklings of the eye form one kâṣṭhâ, thirty kâṣṭhâs make one kalâ A muhûrta is made up of thirty kalas and one day and night consists of thirty muhûrtas The Sun divides the day and night, the night is for sleep and the day is for work—2 5