Surya Siddhanta
मेषादौ तु सदा वृद्धिर् उदगुत्तरतो +अधिका। देवाम्शे च क्षपाहानिर् विपरीतम् तथासुरे॥
During the half-revolution beginning with Aries, there is always an excess of the day to the north, in the hemisphere of the gods—greater according to distance north—and a corresponding deficiency oT the night ; in the hemisphere of the demons, the reverse.
english translation