The Devi Bhagavata puts it thus: -
"During the first quarter of the Ardra constellation, the Earth remains in her menses. The name of the Earth in menses is Ambuvaci; your worship will be done on a day when that flow is stopped.
" The Devi Bhagavata continues: -
"Oh Sankari, one should not dig the earth even by the tip of a needle. One should avoid sowing seeds for 24 praharas (i.e. for 72 hours). If one sows by mistake, one should allow the cattle to eat the shoots up. If one eats, one should perform a penance of Krchhra, and if one digs, one should perform a titakanchana (i.e. make a gift of sesamum and gold), for (on that occasion) and the mother goddesses like Durga remain in menses". 22
It is the time of the year when the Mother Earth attains her fertility to conceive the crops. The agriculturists; particularly in Assam take this time of the year to sow their first seedlings of the Sali paddy, which is transplanted after a few weeks. To symbolise the occasion only red flowers, red vermilion, etc., are used. Red colour signifies the menstrual flow. On this occasion pieces of red cloth, with the deity’s menstrual blood, are given to the votaries as sacred symbols. This fair subsists even at present.
The Debaddhani festival is held in connection with the Manasa Puja. It is so called because of the tremendous sound produced by the instruments such as drum, Dhole, etc., used on the occasion. The worship of the goddess Manasa is a living and powerful cult in Assam. She is worshipped with much adoration and ceremony particularly in the districts of Kamrup, Goalpara and Darrang. She is also worshipped by the Kacharis. She is generally worshipped in the months of Jaistha, Asadha, Sravara and Bhadra, and also during times of pestilence and disease.
22. Quoted from Fairs and Festivals of Assam, p. 30