On What Basis Are Hindu Months Named

When the month names of the Hindu calendar such as Chaitra, Vaishakha, Jyeshtha or Ashadha are heard it is natural to wonder where these names came from. In ordinary conversation people only know that there are twelve Hindu months, yet the deeper astronomical and Vedic basis behind these names usually remains unknown. In truth there is a close link between the Hindu months and the nakshatras, the lunar mansions and the central idea of a month is firmly rooted in the moon.

In Sanskrit one meaning of the word masa is Chandra, the moon. From this same word the common form mah in Hindi evolved. In the moon related word masa the consonant sa gradually changed into ha to form mah. In Vedic mantras the moon is described as the maker of the months because knowledge of the month arises from the motion and phases of the moon. For this reason when Hindu months are mentioned the primary reference is to the chandra masa, the lunar month.

How many kinds of months are recognised

From religious and astronomical viewpoints several kinds of months are taught. The main types can be listed as follows.

• Chandra or lunar month
• Solar month
• Nakshatra month
• Savana month

In actual practice the system followed most widely is that of the lunar month. Therefore when the word masa is used in common speech it is generally understood to mean the lunar month.

On what basis are lunar month names decided

The basis of the lunar month is the full moon or purnima. The principle is clearly stated that on the day of purnima the nakshatra in which the moon is placed gives its name to that lunar month.

A well known verse of the lexicon Amarakosha explains this rule.

Pushyayukta paurnamasi paushi mase tu yatra sa
namna sa pausho maghadyash chaivam ekadasha apare.

The meaning is that the full moon which rises in the sky together with the Pushya nakshatra is called paurnamasi paushi and the month in which such a full moon falls is known as Pausha masa. In the same way the remaining eleven months are also named according to their respective nakshatras.

Month names derived from nakshatras

On the day of full moon the nakshatra occupied by the moon gives the month its name. The traditional correspondences are as follows.

• Chaitra is the month whose full moon falls when the moon is in the Chitra nakshatra.
• Vaishakha is the month whose full moon appears with the Vishakha nakshatra.
• Jyeshtha or Jeth is the month whose full moon occurs when the moon is in Jyeshtha nakshatra.
• Ashadha is the month whose full moon arises with the Uttara Ashadha nakshatra.
• Shravana is the month whose full moon is linked with the Shravana nakshatra.
• Bhadrapada is the month whose full moon falls when the moon is in Uttara Bhadrapada nakshatra.
• Ashwin is the month whose full moon occurs with the Ashvini nakshatra.
• Kartika is the month whose full moon appears when the moon is in Krittika nakshatra.
• Margashirsha is the month whose full moon is in the Mrigashira nakshatra.
• Pausha is the month whose full moon is joined with the Pushya nakshatra.
• Magha is the month whose full moon happens when the moon occupies the Magha nakshatra.
• Phalguna is the month whose full moon falls in the Uttara Phalguni nakshatra.

In this way every lunar month name is directly tied to a particular nakshatra and that link is defined by the position of the moon on the day of full moon.

What are Shukla paksha and Krishna paksha

Within one month two clear phases of the moon are recognised, known as paksha.

• Shukla paksha is the period that begins from Pratipada and extends up to Purnima. During this time the visible disc of the moon increases day by day.
• Krishna paksha is the period that starts from Pratipada and continues till Amavasya. In this phase the moon’s light gradually decreases until the dark night of Amavasya.

The duration from Shukla Pratipada to Amavasya or from Krishna Pratipada to Purnima, is called one chandra masa, one lunar month. In the tradition there are two different ways of counting these months.

• In the first method the month ends on Amavasya. This is called the Amanta month.
• In the second method the month ends on Purnima. This is known as the Purnimanta month.

In North India the Purnimanta system is more commonly followed, while in South India the Amanta system is widespread. In a Purnimanta system the month finishes on the full moon day and in the Amanta system the month finishes on the new moon day.

How were months counted in ancient times

In earlier periods the months were mainly reckoned according to the Purnimanta method. This means that the month was understood to end on Purnima.

For example the bonfire of Holika dahan is performed on the full moon of the bright half of Phalguna. On that very day the month of Phalguna ends and with the next Pratipada the month of Chaitra begins. Twelve such months together make up a lunar year of about 354 days.

According to the division of seasons there are six ritus in a year and each ritu contains two months. In the earlier tradition only three main ritus were counted.

• Grishma or summer
• Varsha or rains
• Hemanta or cold

Later these three were divided into two parts each to form the detailed system of six ritus.

• Vasanta
• Grishma
• Varsha
• Sharad
• Hemanta
• Shishira

Thus a consistent harmony was established between lunar months, nakshatras and the cycles of the seasons.

Vedic names of the months

In the Vedic tradition along with the familiar lunar month names a separate set of Vedic month names is also given. These are listed as follows.

• Madhu
• Madhava
• Shukra
• Shuchi
• Nabhas
• Nabhasya
• Isha
• Urja
• Sahas
• Sahasya
• Tapas
• Tapasya

These Vedic names are connected with the seasons and each ritu contains two of these months.

• In Vasanta ritu the months are Madhu and Madhava.
• In Grishma ritu there are Shukra and Shuchi.
• In Varsha ritu there are Nabhas and Nabhasya.
• In Sharad ritu the months are Isha and Urja.
• In Hemanta ritu there are Sahas and Sahasya.
• In Shishira ritu the months are Tapas and Tapasya.

The meaning of each ritu resonates with the meaning of its associated months. When the Vedic sense of these words is understood it becomes clear that the character of Vasanta relates to Madhu, that of Grishma to Shukra, of Varsha to Nabhas, of Sharad to Isha, of Hemanta to Sahas and of Shishira to Tapas.

Brief summary of lunar month, nakshatra and ritu

Basis	What it denotes	Main feature
Word masa	Time unit linked to the moon	Duration known through lunar phases
Chandra masa	Period tied to Purnima or Amavasya	About twenty nine to thirty days
Nakshatra	Star group where the moon resides	Month name derived from that constellation
Amanta month	Month ending on Amavasya	Common in many parts of South India
Purnimanta month	Month ending on Purnima	Common in many regions of North India
Vedic month name	Madhu to Tapasya, twelve names	Direct meaningful link with the seasons

Guidance obtained from understanding the months

If the Hindu panchang is seen only as a list of festivals then its full depth does not become visible. When it is understood that month names arise from nakshatras and that the Vedic names are woven with the nature of the ritus, the very idea of time starts to feel richer and more meaningful.

Anyone who understands this link between lunar month, paksha, nakshatra and ritu is better able to see in which season and in which celestial setting a particular festival, vow or ritual is taking place. With such understanding daily routine, spiritual practice and celebration all align more naturally with the rhythm of nature.

Common questions about month names

What is the main meaning of the word masa in this context?
The word masa is directly related to the moon and the common form mah is derived from this. Therefore when Hindu months are discussed the primary meaning is that of the lunar month.

On what basis are the names of the lunar months chosen?
The lunar month names are based on the nakshatra in which the moon is placed on the day of full moon. For example when the full moon is in Pushya the month is called Pausha.

What is the difference between Amanta and Purnimanta months?
An Amanta month is one that ends on Amavasya, while a Purnimanta month ends on Purnima. The Purnimanta system is followed in much of North India and the Amanta system in many parts of South India.

How many days are there in a lunar year?
Twelve lunar months make up a year of about three hundred and fifty four days, since each lunar month lasts roughly between twenty nine and thirty days.

What is the relation between Vedic month names and the seasons?
The Vedic names such as Madhu, Madhava, Shukra and Shuchi are directly connected with the ritus. Each ritu contains two such months and the nature of the season matches the inner meaning of these month names.