Purushottama Maasa or the extra lunar month, is an accurate method for adjusting the gap between Solar and Lunar Years. It occurs after every 32 months, 16 days and 8 Ghatis. The solar year is made up of 365 days and about 6 hours, and the lunar year is made up of 354 days. Thus there is a gap of 11 days, 1 hour, 31 minutes between the lunar and the solar years. As this gap accumulates each year, it approximates to one month in a period of nearly three years. The concept of Adhika Maasa is unique to the Hindu lunar calendar.
If a lunar month elapses without a Sankranti , then this month without transit is labelled Adhika Maasa The next month will be labeled according to its transit as usual and will be nija or shuddha.
It is also known as Purushottama Maasam and Dedicated to Lord Hari. It is sometimes referred to as Mala maasa. It should be understood that Mala maasas are of two kinds. Adhimaasa and kshayamaasa (excess month and deficit month). A month which has no Sankranti between two Amavasyas is known as Adhimaasa. A month with two Sankrantis in one lunar month (from Amavasya to Amavasya) is called Kshayamaasa. Kshaya masa occurs on the 141st year or 119th year. Kshayamaasa occur in Kartik, Magasira and Pousha and not anyone else. Kshayamasas are not as frequent as Adhimaasas. Whenever an year contains a kshayamaasa , it will have two Adhimaasas., one before and one after the kshayamaasa.
According to Dharma Sindhu Adhika masa occurring once in 3 years is not good for auspicious ceremonies. The duties and Samskras to be avoided in Adhikamasa are: Upakarma, utsarjana, ashtakasrardhas, First tonsure ( chuda), upanayanam ( maunjibandham), wedding, Vastu karma, house warming, diety installation, opening of wells and gardens, new dress and jewellery procurement and adornment, mahadanas like tulapurusha, yajnakarmas, visiting temples that are not visited before, sanyasa, vrishotsargam ( leaving the bull) rajyabhisheka, , namakaranam and annaprasanam, ( where date has anyway expired)
During Purushottama Maasa, people perform various types of religious rituals such as keeping fast, recitation of religious scriptures such as Devi Bhagavatam, Bhagawatam , Vishnu puranam,. The vratas may be of complete fasting with liquids only , fasting with fruits only or fasting with one time vegetarian food only, as per the tolerance capacity of individuals. Any graha dosh or specific dosha nivaran puja performed in Purushottama Maasam to rectify the horoscope gives ten times better result to the individual.
The worship of a saligramam along with Lakshmi yantra or sree yantra is considered to be very beneficial in this month. Saligrama is the form of Vishnu and anyone who performs Puja of saligram in his house need not do any pilgrimage.
Offering Arghya to the Sun and Apoopa (Neyyappam- a sweetmeat prepared with rice, ghee and Jaggery) daanam to a Brahmin is recommended in this month.
Padmini Ekadashi is an auspicious Hindus fasting day that falls on the Shukla Paksha ‘ekadashi’ (11th day of the waxing phase of moon) during the ‘ ‘Purushottama Maasam’. Most of the times, Padmini Ekadashi falls in the month of ‘Adhika Ashada’ of the Hindu calendar. This special period is ideal for seeking forgiveness of sins and for the purification of the mind and body. The story of Kartaveerya and his wife Padmini is associated with this vratam.