Donyi-Polo
Donyi-Polo is a compound expression in the Tani languages of Arunachal Pradesh and Assam in Northeast India, formed from donyi ("Mother - Sun") and polo ("Father - Moon") similar to the concept of Yin and yang. The phrase denotes the sun-moon pair as a single complementary unit, and across the Tani-speaking peoples (the Adi, Galo, Nyishi, Apatani, Tagin and Mishing) it functions simultaneously as a cosmographic term, an ethical vocabulary, a calendrical reference and a marker of common ethnic identity.