One of the widely celebrated Hindu holidays in parts of India is Makara Sankranti. It is a harvest festival and a day on which Hindus both worship the sun god and celebrate the arrival of lengthier days ahead.
Makara Sankranti is based on the coming of the winter solstice, which means it nearly always falls on 14 January on the Gregorian Calendar. This differs from most other Hindu holy days, which have a lunar basis that begets shifting Gregorian dates.
On Makara Sankranti, Indians attend numerous festive events, family feasts, public fairs, bonfires, and other cultural and religious activities. They put up colourful decorations on their houses and go out to fly kites as well. Some children even go door to door, singing songs in exchange for sweets.
Every twelfth Makara Sankranti, a massive pilgrimage some 50 to 100 million strong takes place. People flock, in accord with tradition, to the juncture of the Ganges and Yamuna Rivers to bathe in the holy water after offering their prayers to the sun god.