The festival of Makar Sankranti is celebrated with great pomp across the country. It is also known by names like Khichdi, Uttarayan. On this day, bathing in Ganga along with donations, Surya Puja and Arghya have special significance.
https://www.bhaktvatsal.com/festivals/makar-sankranti-par-surya-ko-arghya-kaise-de
