Sankramanam (सङ्क्रमणम्) means movement – transmigration. Makara (मकर) means the zodiac Capricorn. The movement of the Sun from one zodiac to the other zodiac is called Sankramanam. The Sun takes approximately 30 days to travel through each zodiac. Since there are twelve zodiacs, there are twelve Sankramanams. Of all these twelve Sankramanams, this transition of the sun – the movement of the sun from Sagittarius (Dhanu Rashi) to Capricorn (Makara) is called by the name “Makara Sankranti” which is one of the important festivals celebrated for its spiritual, religious and astrological significance.
Uttarayana marks the beginning of the day for Devatas, and Dakshinayana, the night. Bhisma, the great grandsire of Pandava who had the boon of willful death (इच्छा-मरणम्) waited for Uttarayanam to come before giving up the body. It was on this day, Bhagiratha liberated his ancestors from the curse by doing tarpana. Astrologically, on this day, the Lord Sun visits the house of his Son, Shani and stays with him for a month. With regard to the spiritual significance, Sannyasis who was observing “Chaturmasya vrata”, the vrata consisting of staying in a place for a period of four fortnights come to an end, and they commence their wandering life disseminating knowledge to the seekers.