Gochar explained: transits, sign changes and retrograde motion

What a gochar calendar lists

Gocara comes from go, to move, and chara, going. In everyday Jyotish it means the study of where the grahas are now relative to a birth chart, which our article on transits and Sade Sati discusses. Underneath every such reading lies a simpler, purely astronomical record: a calendar of the grahas' movements through the twelve signs. It lists three kinds of event for each graha:

• Ingress (rashi pravesha): the moment its longitude crosses from one sign into the next.
• Stations: the moments it appears to stop and reverse, turning retrograde (vakri) or direct (margi).
• Combustion (asta): the period when it is too close to the Sun to be seen, ending with its heliacal rising (udaya).

These are computed, not interpreted. Two almanacs using the same ephemeris and the same Ayanāṃśa print the same moments to within a minute or two.

Sidereal signs

Jyotish counts signs in the Nirayana, or sidereal, zodiac, fixed to the stars. Western astrology uses the Sāyana, or tropical, zodiac, measured from the vernal equinox. The two now differ by about twenty-four degrees, the ayanamsa, so a graha enters a sidereal sign only after travelling some twenty-four degrees beyond its entry into the tropical sign of the same name. For the Sun that takes about twenty-four days; for Saturn, about two years. Our calendar uses the Lahiri ayanamsa, adopted by the Calendar Reform Committee of the Government of India in 1955.

Speeds

Each graha's mean period around the sidereal zodiac sets the rhythm of its gochar:

• Chandra (the Moon): about 27.3 days, so roughly two and a quarter days in a sign.
• Surya (the Sun): one sidereal year, about a month in each sign; the solar months are defined by its ingresses.
• Budha (Mercury) and Shukra (Venus): on average they keep pace with the Sun, never straying far from it, but move unevenly around it.
• Mangala (Mars): about 687 days, around six weeks in a sign, longer when it turns retrograde.
• Guru (Jupiter): about 11.9 years, around a year in a sign.
• Shani (Saturn): about 29.5 years, around two and a half years in a sign.
• Rahu and Ketu: about 18.6 years for a full circuit, moving backwards, around eighteen months in a sign.

Retrograde motion

Every graha except the Sun and the Moon spends part of its time apparently moving backwards against the stars. The planets do not reverse in their orbits; the effect comes from watching them from a moving Earth. When the Earth, on its faster inner orbit, overtakes Mars, Jupiter or Saturn, the outer planet seems to slip back for a while, as a slower train seems to move backwards when seen from a faster one. Mercury and Venus turn retrograde when they overtake the Earth on the near side of the Sun.

Retrograde periods recur on a regular rhythm: Mercury about three times a year for some three weeks; Venus every nineteen months or so for about six weeks; Mars every twenty-six months for about ten weeks; Jupiter and Saturn once a year for about four and four and a half months. An outer planet is retrograde when it is opposite the Sun and nearest the Earth, which is also when it is brightest. The texts noticed the link: a retrograde graha scores high in cheshta bala, the motional strength that forms part of Ṣaḍbala.

The siddhantas model the effect with two corrections to a graha's mean motion: the manda correction, for the unevenness of its own orbit, and the shighra correction, which in modern terms reflects the Earth's motion around the Sun. The Sūrya Siddhānta names eight kinds of planetary motion, from vakra (retrograde) and anuvakra to shighratara (very fast). Around 1500 Nilakantha Somayaji's Tantrasangraha revised the model for Mercury and Venus in a way that K. Ramasubramanian and others have read as partly heliocentric†.

A worked example: Guru in 2026 and 2027

Our calendar shows Guru entering Karka on 2 June 2026 and Simha on 31 October 2026, unusually soon after. It turns retrograde on 13 December 2026 at a little under three degrees of Simha, slips back into Karka on 25 January 2027, turns direct on 13 April 2027 and enters Simha again on 26 June 2027. Between 14 July and 13 August 2026 it is asta, hidden in the Sun's glare. A single headline saying "Jupiter changes sign" hides three ingresses and two stations. The texts have a word, atichara, for a graha that runs ahead into the next sign like this and then returns†.

Combustion

When a graha comes within a certain distance of the Sun it is lost in the Sun's light. The Surya Siddhanta gives these distances, the kalamsha, separately for each graha, with smaller values for Mercury and Venus when retrograde; other texts give slightly different figures†. Muhurta texts set aside the periods when Guru or Shukra is asta for certain household ceremonies, which is why almanacs print the asta periods of these two prominently.

The calendar and the reading

The gochar calendar is astronomy: anyone with an ephemeris can check it. What a transit means for a person is Jyotish, read from the Moon sign, weighed against the running Daśā and qualified by rules such as vedha and Aṣṭakavarga, as our article on transits and Sade Sati describes. We keep the two apart so that computed facts are not mistaken for readings.

Try it

The Gochar page lists every sign change, station and asta period of the nine grahas for the year, with a page for each graha. The Transits tool shows today's sky over a birth chart, and the Dasha tool shows the period running alongside.

Taught in

Planetary transits are one of the themes of the 30-hour research component of our Certificate Programme in Predictive Astrology, offered as FORE × Deepanshu Giri Ji. The programme has 60 hours of learning engagement: 30 hours of live teaching on weekends and 30 hours of self-paced research. The fee is ₹35,000 + applicable GST.

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