Sankranti: the Sun's twelve sign entries

A festival set by the Sun

Most Hindu festivals are fixed by a Tithi, a lunar day, and so wander through three or four weeks of the Gregorian calendar. A few are fixed by the Sun, and they barely move. Makar Sankranti is the familiar example: our computation gives 15 January in 2024, 14 January in 2025, 2026 and 2027, and 15 January again in 2028.

Saṅkrānti means "passage" or "transition". It is the moment the Sun's sidereal longitude crosses from one sign, or rashi, into the next: twelve such moments a year, each opening a solar Māsa, or month. In the solar calendars of Tamil Nadu, Kerala, Odisha, Bengal, Assam and Punjab, these are the civil months. In the lunisolar calendars of the north and west they name the lunar months and decide when an Adhika māsa, a leap month, is needed.

Computing one is straightforward. Take the Sun's tropical longitude from an ephemeris, subtract the Ayanāṃśa to get its sidereal longitude, and find the instant when that value reaches a multiple of thirty degrees. The instant is the same everywhere on Earth; only its local clock time differs, along with the local sunrise and sunset that the rules of observance depend on.

Why the Gregorian date hardly moves

The Gregorian calendar is built to follow the tropical year, the cycle of the seasons, about 365.2422 days. A sankranti is measured against the stars, in the Nirayana (sidereal) zodiac, and the Sun returns to the same point among the stars in a sidereal year of about 365.2564 days, some twenty minutes longer. The difference comes from the slow precession of the Earth's axis.

So each sankranti falls, on average, about twenty minutes later each year by the Gregorian calendar, or about one day in seventy-one years. The leap-year cycle adds a small wobble, which is why the date alternates between the 14th and the 15th. Makar Sankranti fell around 13 January in the early twentieth century and will fall around 15 or 16 January by the early twenty-second†.

The solstice that moved away

The names of the sankrantis remember a time when they matched the seasons. Makara Sankranti is called an ayana sankranti, a "turning" one, because the Sun's northward half-year, uttarayana, was reckoned from it. When the sidereal and tropical zodiacs coincided, around the third century CE by the Lahiri reckoning†, the Sun did enter sidereal Makara at the winter solstice. Precession has since separated the two by about twenty-four degrees, the Ayanāṃśa, so the solstice now falls about three weeks before Makar Sankranti, around 21 or 22 December.

Many almanacs still open the northern Ayana at Makar Sankranti for ritual purposes, while others note the astronomical solstice separately. These are descriptions of two different things: one a traditional marker, the other the Sun's actual turning point.

Four classes of sankranti

The texts group the twelve:

• Ayana (turning): Makara and Karka, once linked to the solstices.
• Vishuva (equal day and night): Mesha and Tula, once linked to the equinoxes.
• Vishnupadi: Vrishabha, Simha, Vrishchika and Kumbha.
• Shadashiti-mukha: Mithuna, Kanya, Dhanu and Meena.

Punya kala: the sacred window

A sankranti is a single instant, but bathing and giving are done in a window around it called punya kala. Dharmashastra digests give the window by class. Kamalakara Bhatta's Nirnaya Sindhu, quoting the earlier digest of Hemadri, gives twenty ghatikas (eight hours) after the instant for Makara, twenty before it for Karka, ten on either side for Mesha and Tula, sixty after for the shadashiti signs and sixteen on either side for the vishnupadi signs†. Since these rites are done by daylight, almanacs keep the part of the window between sunrise and sunset, and when the instant falls at night they move the observance to an adjacent day by further rules.

In 2026 the Sun entered Makara at 2:59 pm IST on 14 January. In New Delhi the punya kala therefore ran from that moment until sunset, a little before six.

Festivals of the solar year

Makar Sankranti carries many regional names: Pongal in Tamil Nadu, Uttarayan in Gujarat, Maghi in Punjab, Magh Bihu in Assam and Khichdi in eastern Uttar Pradesh and Bihar; Lohri is kept on its eve. Mesha Sankranti, around 14 April, opens the solar year as Vaisakhi in Punjab, Vishu in Kerala, Puthandu in Tamil Nadu, Pana Sankranti in Odisha, Pohela Boishakh in Bengal and Bohag Bihu in Assam. These festivals stay in the same week of the Gregorian calendar year after year, unlike Diwali or Holi.

What the instant is, and is not

A sankranti is an astronomical event, computed from the Sun's position, and the punya kala is a rule of observance built on it. Neither says anything about the year ahead.

Try it

The Sankranti page lists all twelve sankrantis of the year with their instants and the punya kala for your city, each with its rule. The Makar Sankranti page shows the festival itself, and the Calendar converter shows the solar sign for any date.

† Marked dates or readings are debated among scholars or still being confirmed by our faculty.