We celebrate this festival year after year on 14th January. I am looking at this differently. Why this festival alone, very precisely coming year after year on the 14th January?. Deepavali, Karthigai, Gokulashtami, or Sri Rama Navami, etc are coming on different days. I am giving the full explanation below:
Sankranthi means change- a movement of time, a movement of a month. This is a zodiacal event that takes place on 14th of January year after year. Makara denotes Makara Rasi or Capricorn, the Lord of this house is Saturn. The Sun is shifting from Dhanur Rasi and entering Capricorn. This change is permanent. Every month the Sun is changing residence. Therefore there are 12 sankaranthis per year. There are twelve squares in a horoscope. Monthly Sankaranthi takes place on 14th or 15th of every month depending on the number of days in a month. We called this day January 14th the beginning of Uttarayan Punya Kalam. Bhishma waited to die on this Day. Fixing of festivals in India are based on the movement of Moon, but not Mahara Sankaranthi. Similarly, when the Sun enters Cancer (kataka rasi after six months) it is called Dakshinaya Punya Kalam.
We finish our harvest in India during January, it is a thanksgiving day to the Sun and to farmers who work hard to produce wheat, rice, and pulses for our consumption. We also worship and decorate cows and bulls on the 3rd-day as they contribute to farming. There is another thing, ie, Winter solstice(shortest day in the Western hemisphere), this happens on 22nd of December. This does not coincide with Makara Sankaranthi on January 14th, there is a difference of 23 days. During this 22nd December(this year 2017December 21st Thursday shortest day at 16.38PM), the Sun reaches the maximum angular distance in the south and starts moving towards the north. This is the correct day for Makara Sankaranthi ,uttrayana starts on 21st december 2017. However, we say uttarayana(uttaram-North,ayanam -Change) begins on 14th January every year. There is a reason for this starting of uttrayana after three weeks of the departure of the Sun from the south pole. Looking at the zodiacal arrangement some 2500 years ago, you will notice the Sun entered Makara Rasi on 22nd December. In 1000BC Makara Sankaranthi was observed on 31st December. Why this change? The reason arises from the precession of the axis of rotation of the earth which spins around its axis once in 24 hours, once a day. What is this axial precession? Our earth axis appears stable, but it is not stable. it will wobble like a pambaram or a spinning top. It takes 26000 years to complete a circular wobble or full rotation. This wobble is called precession, it is a slow process. This precess comes from gravitational pulls of the Sun and the moon which try to pull the earth's rotation from perpendicular to elliptic plane, because of this pull north-south climate changes.This precession, this eccentricity determines how much sunshine we get when season changes, this is termed as obliquity.
This change has created 22 days difference, and hence Makara Sankaranthi is on 14th January. The date may change after several thousand years.
The Sun enters his enemy's house(Saturns)as per astrology, As per Hindu legends, Saturn is the son of Sun. We make jaggery Pongal to please the Sun; we also make til balls with jaggery, til to satisfy Saturn. The bond between the son and the father is increased through jaggery. Saturn and Sun combination gives the leadership, dynamism of Sun and thoughtfulness, hard work of Saturn to individuals who are born during this month (January 15th to14th February).