Hindu lunar months follow the cycle of the Moon, but India has two long-standing conventions for where a month begins and ends. Knowing the difference avoids a lot of confusion when a festival seems to be listed under two different months.

The two systems

  • Amanta (ending at Amavasya): the month runs from the day after the new moon to the next new moon. Shukla paksha comes first, then Krishna paksha.
  • Purnimanta (ending at Purnima): the month runs from the day after the full moon to the next full moon. Krishna paksha comes first, then Shukla paksha.

The Shukla paksha always carries the same month name in both systems. The Krishna paksha is named one month ahead in Purnimanta. For example, the dark fortnight that Amanta calls Shravana Krishna is called Bhadrapada Krishna in Purnimanta.

How months get their names

In the drik (astronomical) rule used on this site, an Amanta month is named after the sidereal sign the Sun occupies at the new moon that begins it. If the Sun is in Meena at that new moon, the month is Chaitra; Mesha gives Vaishakha, Vrishabha gives Jyeshtha, and so on through the twelve months. Purnimanta names are then derived from these by shifting the Krishna paksha forward by one month.

Who uses which

  • Purnimanta is used in most of North India.
  • Amanta is used in Maharashtra, Gujarat, Karnataka, Andhra Pradesh and Telangana.

Other regions, such as those following solar calendars, have their own conventions. Traditions vary by region and Panchang convention.

Same festival, different label

The actual day of a festival does not change, because it depends on the tithi, not on the month label. Only its description differs:

  • Krishna Janmashtami is Bhadrapada Krishna Ashtami in Purnimanta and Shravana Krishna Ashtami in Amanta: the same night.
  • Ekadashi names are traditionally cited in the Purnimanta convention, so a Krishna Ekadashi in an Amanta month carries the name of the following month.

On this platform

Your calculation profile decides which system is used for display: the North Indian profiles use Purnimanta, and the Amanta profile uses Amanta. Festival rules are defined once and give the same dates under both. Browse months on the calendar, compare profiles in the methodology, or read about Adhik and Kshaya months.