The Twelve Months of the Hindu Calendar

The Hindu calendar counts its months by the Moon. One month runs from a new moon to the next new moon, or from a full moon to the next full moon, depending on which part of India you are in, and it lasts about twenty nine and a half days. Twelve of those months come to roughly 354 days. The solar year is about 365. That gap of eleven days is why Diwali, Holi and Navratri land on a different English date every year, and it is why the calendar needs a repair mechanism, which it has.

The Twelve Names

The months in order are Chaitra, Vaishakha, Jyeshtha, Ashadha, Shravana, Bhadrapada, Ashwina, Kartika, Margashirsha, Pausha, Magha and Phalguna. Chaitra opens the year with spring, around March or April, which is where Gudi Padwa and Ugadi fall. Kartika closes the festival season with Diwali and the lamps.

Each name comes from a nakshatra, which is one of the twenty seven lunar mansions the Moon travels through. Kartika is named for Krittika, Ashwina for Ashwini, Bhadrapada for the two Bhadrapada mansions, Shravana for the star Shravana. The idea behind the scheme is that the full moon of a month stands in the star the month is named for, and it often still does. In 2026 the Ashwin full moon of 26 October stands in Ashwini, the Kartik full moon of 24 November in Krittika, and the Bhadrapada full moon of 26 September in Uttara Bhadrapada.

That is where the names came from. It is not what assigns them now. The Moon has drifted against the old scheme over the centuries, sometimes by two mansions: the Ashadha full moon of 29 July 2026 stands in Shravana, and the Shravana full moon of 28 August stands in Shatabhisha. Each month keeps its name either way.

What fixes the name in a given year is the Sun. The Sun enters one sidereal sign each solar month, twelve of them in order from Aries, and a lunar month takes the name matching the sign the Sun enters during it. The lunar month the Sun enters Gemini in is Jyeshtha, the third sign and the third month. The one it enters Cancer in is Ashadha, the fourth of each. Run that through 2026 and it puts Ashadha Purnima on 29 July, which is Guru Purnima, and Shravana Purnima on 28 August, which is Raksha Bandhan.

Purnimanta and Amanta, the Same Month Twice

Here is the part that confuses almost everyone, including people who have kept these festivals all their lives. India runs two reckonings of where a month begins.

In the north, across Uttar Pradesh, Bihar, Punjab, Haryana, Rajasthan and Madhya Pradesh, the month ends at the full moon. This is Purnimanta reckoning, and it means the dark fortnight comes first and the bright fortnight second.

In the west and south, across Maharashtra, Gujarat, Karnataka, Andhra Pradesh, Telangana and Tamil Nadu, the month ends at the new moon. This is Amanta reckoning, and the bright fortnight comes first.

The two systems keep every festival on exactly the same day. What differs is the label. Krishna's birth falls in a dark fortnight that the north calls Bhadrapada and the west calls Shravana, so the same night is Bhadrapada Krishna Ashtami in Varanasi and Shravan Vad Ashtami in Pune. The ancestral fortnight of Pitru Paksha begins after the Bhadrapada full moon, and the north counts it as Ashwin's dark half while the west counts it as Bhadrapada's. If a relative gives you a month name you did not expect for a festival you both keep on the same date, this is why, and neither of you is wrong.

Why the Festivals Move Against the English Calendar

A lunar year of 354 days runs eleven days short of the solar year, so left alone each festival would slide eleven days earlier every year. Three years of that is thirty three days. Diwali would leave autumn and land in the monsoon, and the harvest festivals would arrive before the harvest.

The calendar prevents this with an extra month, and the rule for when to insert one is exact rather than a matter of judgement. The Sun spends about thirty and a half days in each sidereal sign, which is slightly longer than a lunar month. Sooner or later a whole lunar month passes without the Sun entering any sign at all. Such a month has no name of its own to take, which is exactly the problem, and it is declared an extra one.

Adhik Maas, the Thirteenth Month

The extra month is called adhik maas, and it arrives roughly every thirty two or thirty three months. It takes the name of the real month that follows it, so an extra month before Jyeshtha is Adhik Jyeshtha, and the real one is then called Nija Jyeshtha.

It is also called mal maas, the impure month, and this is where the tradition does something worth knowing. A month with no solar sign change was treated as inauspicious and nobody wanted to own it. Weddings, house warmings, thread ceremonies and new ventures are still held off through it. The story goes that the unwanted month appealed to Vishnu, who took it as his own and gave it his name, so it became Purushottam maas, the month of the supreme being. The leftover month became the one recommended for reading, chanting, charity and pilgrimage, and merit earned in it is held to count for more than usual. If you are waiting out an adhik maas for a wedding date, that is the month's own instruction on what to do with the wait.

The 2026 Window

2026 carries an adhik maas, and it is why every festival this year falls about a month later than it did in 2025.

The Sun entered sidereal Taurus on 15 May 2026, two days before the new moon of 17 May. It entered Gemini on 15 June, a few hours after the new moon of that same morning. The lunar month between those two new moons, 17 May to 15 June 2026, therefore contains no solar sign change at all, which makes it an extra month. The real Jyeshtha follows it, 15 June to 14 July 2026, and that is the month the Sun enters Gemini in, which is what names it. The extra month borrows that name, so 2026 runs Adhik Jyeshtha and then Nija Jyeshtha.

Everything downstream shifts with it. Reading the four festival months in Purnimanta reckoning, Shravan runs 30 July to 28 August 2026, Bhadrapada 29 August to 26 September, Ashwin 27 September to 26 October, and Kartik 27 October to 24 November. Guru Purnima falls on 29 July, Raksha Bandhan on 28 August, Ganesh Chaturthi on 14 September, Dussehra on 20 October and Diwali on 8 November.

Which Month Presses Hardest on Your Chart

The calendar is the same for every reader of this page. What each month does is not, and the difference is readable in a birth chart rather than a matter of belief.

Three things decide it. The Moon crosses your birth moon sign once in every lunar month, and those two or three days each month tend to run closer to the surface than the rest. Once a year the full moon of one particular month falls in the star you were born under, and that month is usually the loudest of your twelve. And every month is named for a star with a ruling planet, so when a month's planet is also the planet running your current dasha, the period the Vedic system uses to divide a life into chapters, the month's usual advice applies to you with more force than it does to anyone else.

Kartik is named for Krittika, whose lord is the Sun. Shravan is named for Shravana, whose lord is the Moon. Ashwin is named for Ashwini, whose lord is Ketu. Bhadrapada takes the two Bhadrapada stars, held by Jupiter and Saturn. Someone in a Ketu period walking into Ashwin is not having the same October as everyone else.

You need three facts about yourself to use any of this: your moon sign, your birth star, and which planet is running your current period. The free birth chart gives you the first two from your date, time and place of birth, and the free dasha calculator gives you the third.