Sankasthi Chaturthi is observed every Lunar month of the Hindu calendar on the fourth day of Krishna Paksha. If this auspicious day falls on a Tuesday it is called Angaraki Sankashti Chaturthi. Angaraki Sankashti Chaturthi is considered highly important among all Sankashti Chaturthi days.

Angarak means the red color of burning coal and it refers to the color of the planet Mars. As Tuesday is named after the planet, devotees believe that praying on that day benefits them even more. Observing this fast is believed to reduce your problems as Lord Ganesha symbolizes the removal of all obstacles and the supreme lord of intelligence.

According to legend, Lord Ganesha was created by Goddess Parvati, consort of Lord Shiva. She asked him to guard her door while she bathed. Meanwhile, when Lord Shiva returned Ganesha didn't allow him to enter, as he didn’t know him. Lord Shiva became enraged and asked his follower gods to teach the child some manners. Ganesha being born of Parvati was extremely powerful. He defeated the godly-followers called Gana’s and declared nobody was allowed to enter while his mother was bathing. The sage of heavens, Narada, along with the Saptarshi sensed a growing turmoil and went to appease the boy with no results. Angered, the king of Gods, Indra attacked the boy with his entire heavenly army but they too didn't stand a chance. By then, this issue had become a matter of pride for Parvati and Shiva.

After nothing seemed to bring Lord Ganesha down, the trinity, the controller, preserver and destroyer of the universe launched an attack against him. Amidst the fighting, Shiva severed the head of the child. This angered Parvati as she saw her son dead. Parvati revealed her true self, as the Adi-shakti, the prime energy that fuels the universe and sustains matter. Taking on a terrible form, she vowed to destroy the universe where her son was killed and re-create a better one. The Gods prostrated before her and Lord Shiva promised that her son will live again. The trinity hunted the world for a head and came across a mother elephant crying for her dead baby. They consoled the mother and fixed the head of the baby elephant in place of Ganesha's head. Lord Shiva also declared that from this day, the boy would be called as Ganesha. In this way, Lord Ganesha came to be depicted as the elephant-headed God.