In days of yore, there were cannibals Cannibals in India. They did much havoc. They threatened the living young, one of them was Holika (Putana). She took immense delight in devouring children. Lord Krishna destroyed her and saved the little children. The effigy or figure of Holika is burnt in the fire even now on this day. In the Southern India, the figure of cupid made of clay is burnt. This is the origin of the great festival Holi.
Holi is known by the name of Kamadahana in South India, the day on which Cupid was burnt by Lord Siva.
P-30 - It is like the April fool day of the Europeans.
People perform Havan & offer the new grains that are harvested to the lord & then use them.
Makara-Sankranti
H.F.J.P.S Their Philosophy Sivanand P-39
Makara-Sankranti is the commencement of the sun's northern course in the heavens.
...this is when I attend a northerly course in the heaven. (उत्तरायण)