The month Mārgaśīrṣa, the 9th month of the Hindu calendar year (corres-ponding to November-December) is called Agrahāyaṇa (‘beginning of the year’). According to the writings of the foreign travellers visiting this country like Al Beruni (A. D. 1030) and borne out by the internal evidence in the Mahābhārata (Anuśāsanaparva 106.17-30) the year began with Mārgaśīrṣa. Hence the name Agrahāyaṇa. The rite performed on the full-moon day of this month is called ‘āgrahāyaṇī.’
An important part of this rite is pratyavarohaṇa (‘descending again’) signifying the ceremonial descent of the entire family from a high cot or, couch which was being used from the month of Śrāvaṇa (corresponding to July-August) for fear of snakes. Hence this is sometimes considered a part of the snake rite.
After uttering the prescribed mantras (which contain prayers to snakes not to harm the family) and offering pāyasam (milk-rice pudding) to them, the entire family comes down the high cot and sleeps on the bed of straw or grass newly prepared.
On this occasion the house is usually replastered and painted, if not renovated.
In some works pratyavarohaṇa is mentioned as a separate rite to be performed at the beginning of each of the six seasons.