Kautilya's Arthashastra 2.29.32

2.29.32

dvitīyakāladogdhur aṅguṣṭhacchedo daṇḍaḥ //

During the rainy, autumnal, and the first part of winter (hemanta) seasons, they shall milk the cattle both the times (morning and evening); and during the latter part of winter and the whole of the spring and summer seasons, they shall milk only once (i.e., only in the morning). The cowherd who milks a cow a second time during these seasons shall have his thumb cut off.