Makar Sankranti – Festival of kites, bullfights & bonfires

When Celebrated –
The festival is celebrated on 14th of January, all over the country with festive fervour.

Why Celebrated - Significance

1. On this day, Sun travels from Tropic of Cancer to Tropic of Capricorn (Makar). The movement is called Uttarayana.
2. The festival is an occasion of sharing and goodwill.
3. In many states, it is harvest season.
4. As per Hindu calendar, it is very auspicious.

How & Where Celebrated

1. In Punjab – The festival is called Lohri. It is celebrated on 13th January with huge bonfire and baked rice & sweets (Raveri) are offered to fire and distributed among friends & relatives.

1. In North & west – The festival is called Makar Sankranti. People donate rice, pulses etc.  People offer a prayer to the sun and prepare Khichdi. Churma of ghee, halwa and kheer are cooked specially in Jats and Yadavs homes on this day. Magha Mela is organized in parts of central and north India.
2. In Bihar & Jharkhand, people start their day by worshiping and putting til (sesame seeds) into fire followed by eating "dahi-chuda", a dish made of beaten rice 
3. In Maharashtra, people exchange multicoloured halwa (sugar granules coated in sugar syrup) and til-gul laadoo (sweetmeats made from sesame seeds and jaggery). People take a holy dip in rivers, especially Ganga, Yamuna, Godavari, Krishna and Kaveri.
4.  In Tamil Nadu – The festival is called Pongal. It is celebrated by making different types of rice preparations. Bull fights events are also held.
5.  In Andhra Pradesh & Telangana – It is called Pedda Panduga.
6. In Karnataka – This is harvest festival during which plates containing white sesame seeds (Ellu) mixed with fried ground nuts, cut dry coconut and jiggery (Bella) are exchanged among families. The mixture is called "Ellu-Bella". This ritual is called "Ellu Birodhu."
7. In Assam – The festival is called Magh Bihu or Maghar Domahi. It marks end of harvesting season and is celebrated with feasts, pot breaking games (Bhonga), buffalo fight and bonfires. During Magh Bihu people of Assam make cakes of rice with various names such as Shunga Pitha, Til Pitha etc. and some other sweets of coconut called Laru or Laskara.
8. In Gujarat – The festival is called Uttarayana. On the occasion, rooftops and terraces are filled with young & old people participating in kite competitions. Skies are filled with colourful kites.

Celebrated since when
It is believed that the festival is celebrated over 5000 years ago as the epic Mahabharata has mention of Magh Mela.


References:
https://en.wikipedia.org/wiki/Makar_Sankranti