Dhanurmas is a name given to a period of nearly one month. Dhanurmas starts with Margashirsha shukla ekadasi (the eleventh day in the bright half of the lunar month of Margashirsha) and extends up to the end of Dakshinayana. This period ends with the Makar Sankranti - the end of dakshinayana mostly occurs during the Pausha

Pausha

Pausha is a month of the Hindu calendar In the Indian national calendar, Pausha is the tenth month of the year, beginning with the solstice on 22 December and ending on 20 January....

month of the Hindu

Hindu

Hindu refers to an identity associated with the philosophical, religious and cultural systems that are indigenous to the Indian subcontinent. As used in the Constitution of India, the word "Hindu" is also attributed to all persons professing any Indian religion...

 Lunar calendar. More appropriately, the start of the Dhanurmas is marked by the entry of the Sun in the Dhanur Rasi (Saggitarius); this is called Dhanuh Sankramana. During this month, the sun transits the Dhanur Rasi and enters the Makara Rashi at the end of this month. Dhanur Mas is not an independent month in any Hindu calendar. The period when the sun starts moving northward from the Topic of Capricorn to the Tropic of Cancer is called uttaraayana. The opposite period when the sun moves southward is called dakshinaayana.

Other Names

Dhanurmas or Dhanur Masa is also known by the names Chapa Mas, Kodanda Mas, Karmuka Mas etc. Chapa, Kodanda, Karmuka etc., in Sanskrit are synonyms of Dhanus; meaning a bow. Dhanurmasa is also called as Shoonya Masa because it is considered as inauspicious to do any good things other than Godly & Holy functions.

Etymology and significance

This period of month is considered as highly auspicious for Vishnu devotees. Old Hindu scriptures have set apart this month to be completely focused on devotional activities. Other non-devotional social activities (such as weddings) are prohibited during this month so that attention can be given exclusively to the worship of God without any diversions. In South India, especially the Vaikunta Ekadasi, which falls during Dhanur Mas, attracts thousands of devotees. Temples conduct special pujas during this period.

Sri Krishna in Bhagavad Gita

Bhagavad Gita

The ' , also more simply known as Gita, is a 700-verse Hindu scripture that is part of the ancient Sanskrit epic, the Mahabharata, but is frequently treated as a freestanding text, and in particular, as an Upanishad in its own right, one of the several books that constitute general Vedic tradition...

, says
मासानां मार्गशीर्षोहम् 10.35.
I manifest more in Margashirsha Maas among the different months in a year.

According to tradition, the Gods wake up early in the morning during the month of Dhanurmas. They perform special prayers to Sri Maha Vishnu during the auspicious period of "Brahm Muhurta", which is one and half hours before sunrise. During this month, devotees offer prayers to the Lord very early in the morning. The month of Dhanurmas is considered a very special month for performing Puja of Vishnu.

Dhanurmas Phal Shruti: Worshiping Vishnu on a single day during this auspicious period is equal to worshiping Vishnu with devotion for 1000 years. Every single step taken towards the nearby lake, river etc. for morning dip during this month brings forth merit equal to performing an Ashvamedha Yaga.

During this period the sun is in the Sagittarius

Sagittarius (astrology)

Sagittarius is the ninth astrological sign in the Zodiac, which spans the zodiac between the 240th and 269th degree of celestial longitude...

or "धनु राशि",the period when the sun passes from Sagittarius to Capricorn or "मकर राशि" is considered as a period of scarcity to the plenty in India. Feeding or giving alms to the deserving poor and Brahmin

Brahmin

Brahmin Brahman, Brahma and Brahmin.Brahman, Brahmin and Brahma have different meanings. Brahman refers to the Supreme Self...

s during this period is believed to confer great merit ie Punya.