Agni Purana says that the Chaturdashi Vrata should be observed on days of the fourteenth phase of the moon`s wane or increase. A Vrati should observe a fast and worship Lord Shiva, on such a Tithi in the month of Kartika, by respectively observing and performing which for a year; he would be long-lived and able to enjoy all the comforts which this world offers. Similarly a Vrati should practise self-control and live on fruits only, on days of the third, eighth, twelfth, or the fourteenth phase of the moon`s increase in the month of Magha, and worship Shiva, subsequently foregoing the taste of all fruits till the completion of the vow, whereon fruits etc., should be given to the Brahmanas. The Vrata thus practised, is known as the Fala-Chaturdashi, preference being given to the latter Tithi in respect of its observance.

It has been narrated in the Agni Purana that likewise a penitent should fast and worship the god Shambhu on the days of the eighth or the fourteenth phase of the moon`s wane or increase, whereby he would be the happy possessor of all things worth-having in human life, and secure an elevated existence after death. Poles should be set up with streamers unfurled there from, in honour of the god Mahendra, on the occasion of the dark Chaturdashi in the month of Kartika, and the god should be invoked and worshipped over the flagposts.

The Purana mentions that the Vrati should take special care in bathing and absolving himself of all impurities that day, whereby he would attain eternal felicity. Subsequent to that the Ananta manifestation of the god Hari, should be worshipped on the day of the fourteenth phase of the moon`s increase in the game month. The god, as well as the waters of the ocean which forms his abode, should be represented by the blades of holy Kusha grass, tied up in knots, and the penitent should prepare a cake with pasted Shali and powdered sun-dried rice. Half of the cake should be given to a Brahmana, while he should take the other half himself.

It has also been said that the history of the origin of the Vrata, should be recited and heard on the bank of a pond and a string of thread should be tied round the wrist or the throat of the Vrati.