The Puraanas also sing high praises about Adheek Maas and indicate Poojaa, readings of scriptures etc. during Adheek Maas. Selfless actions, without the expectations of results, are to be performed. Mal Maas (Adheek Maas) is the month for Vishnu poojaa. This produce top meritorious results. In addition to singing and listening to the praises of the Lord (Vishnu), undertake Adheek Maas Vrat also. If there is a temple nearby then perform puja of whatever deities are usually worshipped therein. During the entire month of Mal Maas Vrat eat Sattvic food (vegetarian meals, milk, fruits, nuts, grains, vegetables). One meal at night is recommended.
It is written in the Bhavishyottar Purana that Sri Krishna Himself has said regarding Adhik Maas Vrat that by carrying out the Vrat with the sole aim of worshipping God, through fasting, cleanliness, charity, puja etc. merits are acquired which produce unfailing results and all sorts of calamities are overcome
Just as there is the lunar year with the extra month (Adhik Maas), so is there a lunar year with a diminished
or reduced month (Kshaya Maas), with only eleven months in the year. The lunar year comprising of eleven months only is very
rare indeed. But the extra month or Adhik Maas comes every third year. Adhik Maas adopts the name of the month that follows
Adhik Maas. Whenever Sankranti does not fall within one month then Adhik Maas occurs. When there are two Sankrantis within
one month then it becomes the lunar year with one reduced month.
It is written in the Devi Bhagavat that charitable and meritorious acts and fastings etc. carried out during this Mal Maas (Adhik Maas), inevitably produce results. Just as an atomic sized seed contains within it the power to produce a giant and long living Banyan tree, so in the same manner even a little charitable act undertaken during Adhik Maas produces huge results.
There is also a legend that Hiranyakashipu had asked for a boon that no man, animal or sura, asura should cause his death; further he asked that he should not meet his death in any of the 12 months of the year, in the morning or night, not inside the house nor outside, nor by any weapon.
He thought he was being very clever. But the Supreme Lord outwitted him and appeared in Narasimha form, in the evening, during Adhik Mass and dragged Hiranyakashipu to the threshold of the palace (neither inside nor outside) and ripped open his chest with his claws.
Therefore, during Adhik Maas no auspicious festive activity such as marriage, havan, puja anushthan etc., should be performed. Only naam japa, charity and Bhagavat katha yagya should be done.
Mal Maas or Adhik Maas is also known as Purushottama Maas. There is a nice story about this. According to the lunar year, there were only 12 months. Each of the twelve months was assigned to 12 gods. So that the lunar and the solar years do not get out of step with days and seasons, the far-sighted Rishi-Munis calculated and facilitated Adhik Maas (extra month) and showed its importance.
But one problem still remained. Each of the 12 months was assigned to 12 different gods. But the 13th extra month was not assigned to any god. Adhik Maas felt sad and approached Lord Vishnu and said that no god was assigned to him (Adhik Maas) and for that reason he was called Mal Maas (Unclean month). Adhik Maas further prayed to Lord Vishnu: ‘ I am filled with anxiety and I have therefore come to seek your refuge and help.’