The Many Avatars of Hindu Months

Hindu Months Explained.

A few years back, a relative of mine wondered - why is this year's Avani Avittam not happening in the (Tamil) month of Avani?

That can be answered if we get the principles of the Hindu Months. And the month naming system.

Twelve Months

Across the world, the year is divided into twelve months. And it is safe to say, this is true across all traditions of the world.

Now, the question arises - why twelve ? Why not ten months ? Why not twenty ?

In ancient times, people deduced that the yearly cycle was around 360 days. They also figured that the time for Moon to go around the Earth was about 30 days.

So, counting in terms of Moon revolutions - twelve revolutions of the Moon was equivalent of a seasonal year (360 ÷ 30 = 12). Hence twelve months.

In other words, one month is the time span of Moon's revolution around the Earth.

As our ancestors improved on the accuracy of measuring times of these physical events, it gave rise to various calendar systems.

That, then, gave rise to multiple definitions of the Hindu Month !

Month in Chaandramaana

Chaandramaana system might have been the initial calendar system used. Calendar with reference to the Moon.

Here the maasa (month) is defined as the time taken for the Moon to go around the Earth.

Then, it was realized that, the twelve months were not in sync with the seasons. The twelve revolutions of the Moon is about 11 days short of the solar year. So, we end up adding an extra month around every 33 months in the Chaandramaana system.

This extra month is variously called:

  • Adhika Maasa
  • Mala Maasa
  • Purushottama Maasa

The last time we had a Adhika Maasa was in May/Jun 2018. The next time, we will have a Adhika Maasa is in Jul/Aug 2023.

So, that defined the maasa in Chaandramaana system. But, when should the month begin ?

There are two prominent points in the Moon's path around the Earth:

  • When the Moon is nearest to the Sun (Amavasya)
  • When the Moon is farthest from the Sun (Poornima)

Which of the two should mark the start of the new month ?

Moon going around the EarthChaandramaana Hindu Months start at 0° (Amavasya) or 180° (Poornima)

To our luck, (or is it bad luck ?!!) some of our ancestors chose the first option and the rest the second option.

Thus, we have two traditions on how the Hindu months are defined within the Chaandramaana system.

One which used the end of Amavasya as the end of present maasa and the start of next maasa. That system is called Amaanta.

And the other set of traditions chose the the end of Poornima to start the new month. That's known as Poornimaanta.

India map with Narmada and showing Poornimaanta and Amaanta traditions of defining Hindu MonthsDarker regions start Lunar Hindu Months after Amavasya (Amaanta). The lighter regions start after Poornima (Poornimaanta)

The map shows the regions/ traditions that follow the two systems.

The darker regions are the traditions that define the new month after Amavasya. (That would be - Assam, Tripura, Bengal, the southern states, Maharashtra, Gujarat).

The light shaded regions start the month soon after Poornima ends.

Smriti and Jyotisha texts mention that Narmada is the boundary that separate these two traditions. Poornimaanta, north of Narmada and Amaanta south of it.

As you can see from the map, that border no longer holds true in the strict sense.

Sauramaana Maasa

Over a period of time, some of our ancestors deviced a Sun based time-keeping (Sauramaana). In this system, the month is defined by the time Sun is in one of the twelve Raashis.

Raashi (Zodiac) is nothing, but dividing the Sun's path in the sky into twelve parts. And giving a name for each of the parts.

So, the Sun traversing one Raashi constitutes one month in the Sauramaana calendar.

Since the path is not a perfect circle, number of days in a maasa is not equal. It could be as less as 29 days. And as much as 32 days.

Hindu Months' Names

The Chaandramaana maasa names in Sanskrit are based on a pattern. Each month name is derived from the nakshatra of that month's Poornima.

So, if the Poornima Moon is at nakshatra Chitra, that whole maasa is Chaitra. Similarly, we have, Poornima at nakshatra Shravana and hence the name of the month is Shraavana.

Here is the list of Chaandramaana month names.

All Chaandramaana traditions follow these month names with small regional variations.

In the Sauramaana, Sanskrit month names are the Raashi names. Each month name being the Raashi in which the Sun is, for that month.

So, we have Mesha, Vrishabha, Mithuna, Kataka, Simha, Kanyaa, Tulaa, Vrishchika, Dhanus, Makara, Kumbha, Miina. These are Sauramaana month names in Sanskrit.

'In Sanskrit' is the key phrase. Because, most regional traditions do not use those names.

Now, there are seven broad traditions that use the Sauramaana as the primary calendar. Out of that, Malayalam traditions follow the Sanskrit naming system. The rest ... ?

... use the Chaandramaana maasa names for the Sauramaana system.

For example, the Tamil month of Kaartika is actually the eighth month of the Sauramaana (Vricchika) and has very little to do with the Chaandramaana month of Kaartika.

In the Bengali calendar, the month of Faalgun is derived from Sanskrit Phaalguna, a Chaandramaana month. However, Faalgun denotes the eleventh month of Sauramaana (Kumbha).

The first time I discovered this, I wondered - why would people do this? Why mix up two different systems?

The explanation I could think of:

  1. at sometime in the past, all traditions used the Chaandramaana calendar
  2. then some of the traditions decided to move to the Sauramaana system for day to day time tracking
  3. while retaining the Chaandramaana system for festivals
  4. when they moved to the new system, they retained the same (Chaandramaana) month names

That brings us to Avani Avittam question that I mentioned in the beginning.

The name Avani Avittam was probably in use before the change to Sauramaana. Then the definition of Avani maasa changed. Festival didn't. Of course, now, Avani Avittam has no connection with the Avani maasa.

An analogy, I could think of - I have a recipe which says sugar-2kg; then the definition of kg changed to ten times the current weight; generations later someone makes the sweet using the '2'kg sugar; Of course, its too sweet !!


It helps to know the history of Hindu traditions. And definitions of various time spans. We just saw some definitions of Hindu months.

› Hindu Months

New! Comments

Have your say about what you just read! Leave me a comment in the box below.

Subscribe to Receive Free hinduinside.com Newsletters