Hindu Calendar- Era
ब्रहस्पती चक्र or Jovian Cycles
The cycle of Jupiter is considered as one of the most ancient chronological systems, not only in India, but in Tibet, China, and Myanmar
But why did Jupiter cycles come into
prominence? I think, just as we count short periods
- From sunrise to sunrise – One day
- From lunation to lunation of Moon- One Month
- From season to season – One Year. A twelfth part is one month
- Jupiter’s orbit around the Sun is 12 years. A twelfth part is one Solar year or a Jovian month.
Jupiter takes about 12 years to complete
a round of the zodiac. (Actually, it takes 4332.59 days or 11.862 years)
This method was easy to monitor, time longer than one year, as one could observe Jupiter returning to its original position at the end of 12 years. Observing a 60-year cycle was not practical and was hence calculated as per siddhantas and Karana works.
Jupiter has two cycles, the 12-year and 60-year cycles, which were/are being followed. The 60-year cycle originated from the original 12-year cycle of Jupiter.
12-year Cycle of Jupiter
The Vedic people observed that Jupiter takes about 12 years to complete a round of the zodiac. In fact, the orbits of the Sun and Jupiter are around the Barycenter, so the Sun also orbits around Jupiter in 11.8 years.
The word संवत्सर was initially used in the sense of Jovian year. This 12-year cycle is of two kinds. In one case, the संवत्सर receives its name from the heliacal rising. Two consecutive heliacal rising of Jupiter will be a Jovian month or a Solar year. These Jovian months /Solar years were called चैत्र संवत्सर, वैशाख संवत्सर and so on. This system is known as ‘उदयपद्धति. ’ In a 12-year cycle, there will be 11 heliacal risings; therefore, one samvatsar is suppressed/expunged. This system was found inconvenient however, it was in use up to the 6th century CE. This system has references in Mahabharat texts and hence is the original system. This system was in use in the Tamil and Telangana areas. Several inscriptions on stones and copper plates around the period 397 to 450 saka (475-528 CE) in the Gupta era have used this system to denote years.
Inscriptions belonging to King Mrigverma of the Kadamba dynasty mention the years as महा पौष, महा वैशाख, indicating this type of Samvatsar.
The other system, which uses the correct mean motion of Jupiter, its transit through one zodiac sign was considered as one year. In this system, no samvatsar was suppressed. It is called ‘मध्यम राशि पद्धति’ This system is in use as of date but not utilised for civil purposes.
60-Year Cycle of Jupiter
Vedang Jyotish refers to a system of 5
years yug, considering this as Jovian year, this led to a cycle of 60 years.
As stated earlier, the word संवत्सर was used in the sense of the Jovian year. The solar year was called वर्ष. There was also a system of assigning names to years, starting with प्रभव,विभव, and शुक्ल….. up to क्षय, a total 60 years in order. . Since this 60-year cycle originated from Jupiter’s movement, they are also called ब्रहस्पती चक्र or Jovian years. The sixty संवत्सरare divided into 3 groups of 20 संवत्सरeach. The first 20, from प्रभव to व्यय, are assigned to ब्रह्मा ,the next 20 from सर्वजित् to पराभव to विष्णु and the last 20 to शिव
In the beginning, the संवत्सर were counted from the heliacal rising of Jupiter, but later, this system was abandoned, and the mean sign system was adopted. As the length of a Jovian year is less than the solar year, 86 Jovian years occur in 85 Solar years. So 1 year in 85 years has to be suppressed.
As stated above, a shift to the Luni solar calendar made calculations easier and hence most of southern India adopted this system wef Saka 827 (905 CE). Due to this, the samvatsar years began to lag behind those mentioned in northern India for the same year. Today, there is a mismatch, and there will be different samvatsar for the year, depending upon the system and the era being followed.
सूर्य सिद्धांत,ज्योतिषतत्व ,आर्य सिद्धांतgive out the rules of calculating the samvatsar. All three have a different datum of Jupiter's motion for calculation. These rules can be seen from the references given below.
Jovian cycles in other countries
These 12 and 60-year cycles were and are in use in Tibet, China, and Myanmar.
Tibet. There are two series of Jovian cycles. One is a translation of Indian names, and the other is a translation of Chinese names. The Tibetan calendar closely resembles the Hindu calendar. Tibetans calculate their ages using a 12-year Jovian cycle, while other life events are measured using a 60-year cycle. Both cycles have unique names and sequences that are similar to those in the Hindu tradition. There is no suppression of a Jovian year.
China. Chinese Lunar calendar follows a 12-year cycle, and each year is represented by an animal which form the Chinese zodiac. The cycle repeats after 12 years. This was the basis of their 60-year cycle, with names for each year. Their days are distributed in the calendar into cycles of 60, which repeat after 60 years.
Myanmar. Inscriptions found in Myanmar during the period 11th to 13th century CE indicate the use of Jovian cycles. One such translated inscription of Pagan mentions a date as ” In the era 551(1189 CE) Tharawan year…” here Tharawan is Indian Shravan, however 1189 CE corresponds to Maha Jyestha, but 1191 CE / 553 is Maha Shravan. The method of dating indicates that the Jovian cycle was in use along with a similar Hindu calendar.
Common to all these measurements is the Jupiter transit in the zodiac, which has triggered the formation of various systems and methods of accounting epochs.
Trivia and Usages of 12-year cycles
These Jovian cycles of 12 and 60 appear to have been in use in day-to-day life from early times. Attaining 60 years of age is celebrated all over India in some form. Jupiter, Saturn and the Sun have orbital periods of 12, 30, 1years (approximately) around the earth. LCM of these is 60, and all three have the same sidereal coordinates where they were 60 years before.
- Vanvas for Pandav’s was for 12 years +1 year of hiding. Was it due to the Jovian cycle? 1 year of hiding to cater for the lapsed year?
- Mahamastakabhisheka is an important Jain festival held once every 12 years.
- Kumbh Mela. This Mela is held every 12 years based on the position of Jupiter
- The 12-year cycle Mahamaham festival in Tamil Nadu is observed in the Hindu calendar month of Magha and is a symbolic equivalent of the Kumbh Mela.
- As per old Malabar law, “Kanam” was one of the modes of land tenures prevalent in the erstwhile Malabar, including the present Kozhikode District. It was the ‘highest’ form of tenancy. Kanam entrustment was usually for a period of twelve years. Kanom entrustment was renewable at the option of the tenant after the expiry of 12 years.
- Article 65 to Schedule I of the Limitation Act, 1963 prescribes a timeline of 12 years, within which an aggrieved person may file a suit for the recovery of possession of immovable property. (May have been amended as of date)
There are many other aspects which have a 12-year cycle. They may not be connected with Jupiter's transit, but a 12-year period appeared to be a practical duration for counting. A trend set in earlier times continues to this day for civil use, though some of them would have been amended.
How did these cycles originate? It is still unclear, and their purpose and usage remain a mystery. These cycles are still mentioned today in most Panchangs in India.
The current corresponding संवत्सर for 2025-2026 CE. The figure in brackets denotes the संवत्सर number. 1st संवत्सर starts with प्रभव
Saka 1947-विश्वावसु (50th)
Vikram Samvat 2082- कालयुक्त(52nd)
Gujrati Samvat 2081- नल (39th)
It can be seen that संवत्सर are not the same for the reasons mentioned above.
Jupiter’s transit through various signs has
great significance in astrology.
Today, we have vast amounts of texts and treatises available on Jovian cycles. But none can explain the origin and purpose.
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References:-
- Bhartiya Jyotish Shastra-SB Dixit
- The Indian Calendar- Robert Sewell and SB Dixit
- Cowasjee Patells Chronology
- The book of Eras- Gen A Cunningham
- Calendar Reforms Committee Report
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