Markandeyapurana 46.25

46.25

taiḥ ṣaḍbhirayanaṃ varṣaṃ dve 'yane dakṣiṇottare /
taddevānāmahorātraṃ dinaṃ tatrottarāyaṇam //

A kāṣṭhā is said to be composed of fifteen winks of the eyelids; and thirty kāṣṭhās make a kalā; and thirty such kalās make a muhūrta. A day and night among men contain, it has been settled, thirty muhūrtas; and with thirty days are reckoned the two lunar fortnights and the month; of six months consists the sun’s half-yearly course; the two half-yearly courses on the south and north of the equator coinpose the year. Such a year is a day and night of the gods;[8] the day thereof is the sun’s northern half-yearly course.