Narapatijayacarya 3.1.3.15-2

3.1.3.15-2

ādau candraḥ site pakṣe bhāskarastu sitetare ||
pratipadādito hānistrīṇi trīṇi kramodayaḥ ||

At the beginning [of the day] is the Moon in the bright fortnight, but the Sun in the other [fortnight].
Starting from the first lunar day, [each runs for] three [days]; the rise is sequential in triads.