Kalashtami, also known as Kala Ashtami, is observed every month during Ashtami Tithi of Krishna Paksha. Devotees of Lord Bhairav fast and worship him on all Kalashtami days in the year.

According to legend, when Lord Brahma insulted Lord Shiva, Kala-Bhairava appeared from the angry Lord Shiva's forehead and severed Lord Brahma's head, leaving him with only four heads. The head of Lord Brahma stuck to Bhairava's left palm due to the sin of killing Lord Brahma, the most learned Brahmin – Brahmahatya. To expiate the sin of Brahmahatya, Bhairava had to perform the vow of a Kapali: wandering the world as a naked beggar with the skull of the slain as his begging bowl. Bhairava's sin was finally expiated when he reached the holy city of Varanasi, where a temple dedicated to him still exists.

It is believed that chanting the Kala Bhairava Astangam is very beneficial. When a person prays to the lord, he is freed from fear, obstacles and sorrow and at the same time due to this divine God's grace a person gets instant enlightenment, is free from debts, cured from illness and attains sudden prosperity.

Normally,  the 8th day of the waning moon of every month is considered an auspicious time to get the blessings of Kala Bhairava. This year, December 2nd happens to be the 8th waning moon, which is a good day to worship this deity who is capable of fine-tuning a person's time concept. Special rituals are done in temples for Kala Bhairava on this day.