Margaseersha also named as Agrahayana is the ninth month in a Hindu calendar starting from Chaitra masam. The word Agrahayana means the month of equinox. In olden times the year used to begin with Margasira Masam. This month is named after the star Mrigasira when the full moon day coincides with Mrigasira constellation and that month is denoted as Margasira Masam. During the month Sun will be transiting in Scorpio sign (Vrischika raasi) and will be entering into Dhanus raasi in the middle of the month when it is known as Dhanurmasam. It marks the beginning of a new season called Hemantha Ruthu that generally occurs during the calendar months of November and December.
Lord Sri Maha Vishnu in the name of Keshava is the presiding Deity (Masa Niyamaka) who governs this month of Margasira masam. We find Lord Sri Krishna being referred to as Keshava. In 24 Keshava Namas the very first name that we recite is Om! Keshavaya Namah! In Bhagawadgeeta we find Arjuna addressing Lord Sri Krishna several times as Keshava. In Sri Vishnu Sahasra Nama Sthothram we find a reference to the word Keshava in sloka ..
Kalaneminiha virah saurih sura-janeshvarah Trilokatma trilokeshah keshavah keshiha harih
Kesha is a Sanskrit word meaning hair or a ray of light. Keshava means the one who has got a long and beautiful hair, whose hair is very charming, filled with supreme fragrance. Keshava is the one who is endowed with the rays of light spreading within the orbit of the Sun, one who is the Lord of creation, preservation and destruction, one who is the origin of Brahma and Shiva, one who is the tormentor of his enemies, and the one whose, very chanting removes sorrows and sufferings. Keshava also means the one who has slained the demon Keshi and hence is referred to as Keshiha.
Margasira masam is a highly meritorious month for worshipping Lord Sri Maha Vishnu, Goddess Sri Maha Lakshmi and Sun God apart from Lord Hanuman and Lord Subramanya. Several religious events occur during the month of Margasira.
Dedicated to Lord Subramanya, sixth day of Margasira masam, sukla Shasti thithi is known as Skhanda Shasti or Subramanya Shasti or Champa Shasti. We find people worshipping on this day Lord Subramanya who is also known as Skhanda or Kaartikeya. Thaipusam is a special event of this day performed at all the temples of Lord Subramanya especially in South. On this day we find devotees observing an austerity of carrying a Kaavadi (a semicircular decorated canopy supported by a wooden rod) to the temple of Lord Subramanya as a mark of their owe fulfilling for averting a calamity. In some parts of the South we find people observing austerities like fasting, visiting a snake bill, performing pooja and offering milk etc. on this day. Vasthra Dana (a pair of dhoties) to a Brahmachari on this day is considered as highly meritorious. Margasira sukla Ekadasi associated with Dhanurmasam is considered as Mokshada Ekadasi the most auspicious day to worship Lord Sri Maha Vishnu. It is also known as Vaikunta Ekadasi or Mukkoti Ekadasi. Following day is known as Mukkoti Dwadasi. The combination of Uttara Dwara darshanam of Lord Vaikunta associated with Ekadasi thithi has attained significance as Vaikunta Ekadasi. It is said that on this day all the Brahmaadi Devathas visit Sri Vaikuntam to have Uttara Dwara darshanam of Lord SriManNarayana. It is befitting and considered to be the most auspicious day to worship Lord Sri ManNarayana along with Goddess Sri Maha Lakshmi and also to have Uttara Dwara darshana of the Lord on this day. Special celebrations are held at Tirumala, Sri Rangam, Bhadrachalam etc… where thousands of devotees visit these temples to have the Uttara Dwara darshanam of the Lord.
Dedicated to Lord Hanuman sukla Trayodasi in Margasira masam is observed as Sri Hanumad vrata. This is mostly observed in Karnataka and Andhra Pradesh states. On this day Lord Hanuman is exclusively worshipped by one and all for good health, peace and prosperity. It is said and believed that Lord Vedavyasa narrated the significance of this vratha to Dharmaraja and was performed by Draupadi Devi. Significant feature in this vratha is worshipping Lord Hanuman with a yellow coloured thread having 13 knots known as Thora and is worn. Full Moon day in Margasira masam is celebrated as Sri Dattatreya Jayanthi, the day on which Lord Dattatreya regarded as an incarnation of Trinity Lords (Brahma, Vishnu & Maheshwara) was born.
As per Sri Venkatachala Mahatmya it is said that, taking bath in Sri Swami Pushkarini Theertha at Tirumala on the day of Sukla Dwadasi in the month of Dhanurmasam during Arunodaya time is considered as highly sacred and celestial. On this day it is said that, more than three crores of sacred theerthas in the entire Bhoomandala will enter into Sri Swami Pushkarini. Taking bath on this day in Swami Pushkarini is considered highly meritorious and equivalent to taking bath in all the three crores of sacred theerthas. Sapthami, Ashtami and Navami thithi days in the bahula Paksha of Margasira Masam are referred to as Poorvedyu, Ashtaka and Anvashtaka days which are sacred days for performing Pithru tharpana. Geeta Jayanthi the day on which Lord Sri Krishna counselled Arjuna with his famous preaching known as Bhagawadgeeta falls in Margasira masam on the day of sukla paksha Ekadasi. It is befitting to read at least one chapter of Bhagawadgeeta on this sacred day duly understanding its meaning.
Maasaanaam Maargaseersho~ham. In Sri Bhagawadgeeta, Vibhuthi Yoga sloka # 35, Lord Sri Krishna says that, amongst the months He is Margaseersha Masam. These words of Lord Sri Krishna testify the significance given to Margasira masam in the Hindu spiritual calendar.