The following summary on the significance of Purushottama-month is taken from a discourse by His Holiness Srila Bhakti Ballabh Tirtha Goswami Maharaj, President-Acharya of Sree Chaitanya Gaudiya Math and founder of GOKUL.
According to our almanac, every three years, one month is added. This is done to harmonize the lunar month (Chandra-maas) with the solar month (Soar-Maas). The inserted month is known as ‘Purusottama’, and is technically called an ‘intercalary month’. (This year Purushottama month is being observed from 17th June to 16th July.)
Purushottam is the most congenial month for the bhakti-sadhan. Even the aparadhas can be pardoned if we do devotional practice in this month. The Adhishthata (presiding Deity) of this holiest of all months is Bhagwan Sri Purushottam (Sri Krishna) Himself. So, of all the months, this month is the most favorite of the Supreme Lord Sri Krishna. The sadhana (devotional practices) performed in this month will have manifold result.
Everything has consciousness in the background. As per our scriptures, the example is given of the sun, which is presided over by the Sun god, the moon which is presided over by the Moon god and Srimati Ganga Devi, who is the presiding Deity of the river Ganga. Similarly, this Purushottam month has a presiding deity.
It is described in the scriptures that due to being depressed over her seemingly useless existence, the personified deity of this month approached Lord Narayana to question Him. “What offense did I commit? No one is performing any pious activities during my time. Why?”
Lord Narayana directed her towards Lord Krishna. ‘You come with Me,” He said, “I shall take you to Lord Krishna.” Upon being approached by her, Lord Krishna responded, “I am Purusottama, and I cannot be comprehended by finite beings of this world. They cannot comprehend Me by their mental comprehension and sense organs as I am beyond these means.”
Supreme Lord Krishna further explained, “This additional month is like Me. I cannot be comprehended by the conditioned souls of this world. I am supremely superior to Brahman and Paramatma, so I am designated as “Purushottama.” You are identical with Me. You are the holiest month. If anybody observes vrata (vow of austerity) during your time, he can get everything. If as by scriptural injunctions he observes it, it is even more auspicious than Kartik-vrata, the holiest month. So you will be known by the name ‘Purushottama’.”
The Lord of the Universe – Sri Jagannath Dev is also known as Purushottam. Puri is known as Purushottam Dhama. Sree Chaitanya Mahaprabhu used to sing Sri Jagannath-ashtakam, eight verses of the glory of Jagannatha in Puri. So, we may recite the same Sri Jagannath-ashtakam in this Purushottam Maas.
We shall read the glories of Purushottama-Vrata from the writings of Sri Bhakti Vinode Thakur in the morning, daily recite ‘Sri Jagannathastakam’ and ‘Chauragraganya Purusashtakamas’ in the afternoon, and perform silent Japam of this sloka instructed by Kaundinya Muni:
Govardhana-Dharam Vande Gopalam Goparupinam,
Gokulotsavameeshaanam Govindam Gopikapriyam.
Then, in the evening, we offer pure ghee lamp (Deep-dan) before Vishnu. This can be done in a temple of Lord Vishnu, Krishna, Rama or any of Dasavtara.
Lastly, at night we are to read ‘Brahmastava’ 40 slokas, from Srimad Bhagavatam, Chapter 14th, Canto 10th, which includes this verse:
vande navaghana-syam dvibhujam murlidharam
pitambardharam devam saradham purusottamam
“I offer my obeisances to Navaganasyam (Krishna, who has the color of a fresh rain cloud), who is holding the flute with His two hands. I worship Purusottama who is so beautiful in His yellow dress (pitambhara).”
Devotees concentrate on worshipping the Supreme Lord by hearing, chanting and remembering the name, form, pastimes and qualities of Sri Krishna day and night for spiritual benefit only. Reasoning correctly that any tendency for material benefit will certainly divert their minds, they observe this vrata by hearing about Krishna, chanting the Maha Mantra, and taking prasadam. Srila Bhaktivinoda Thakura recommends to follow this path.