Mathematical astronomy is the basis of calendar reckoning, astrology and divination in South Asia. The Indic calendar is, in practice, a complex conjunction of several systems of computing time. Most important among these are the solar, lunar. Jovian and nākṣatra methods of calendar computation. Briefly, the solar (saura) method is a geocentric reckoning based on the sun’s ingression into one of 12 zodiacal constellations. Each zodiac encompasses 30° of the ecliptic. Onesolar day is the time from one sunrise to the next. The lunar (cāndra) scheme is also a geocentric reckoning based on the difference of the longitudinal angle between the sun and the moon. One lunar day (tithi) is the time in which the angular distance of the moon from the sun increases by 12° (1/30 of 360°). The Jovian (bārhaspatya) method is interestingly aheliocentric reckoning used to calculate a cycle of sixty named years. As Jupiter takes 12 years to orbit the sun, 5 orbits constitute 60 years. Finally, the nākṣatra system, which may the oldest method of determining time in South Asia, isa geocentric reckoning based on the moon’s ingression into one of 27 or 28 lunar asterisms. 

 

The Tamil-speaking peoples of South India and Sri Lanka use the solar method to compute the New Year and the harvest festival of Poṅkal. Otherwise, most other festivals celebrated by Tamil speakers are determined by the lunar and nākṣatra systems. The “Tamil” New Year is a bit of a misnomer, and it has never been named as such in pre-modern sources, not least because this New Year based on the pan-Indic solar calendar is also observed in Kerala, Sri Lanka (among Sinhalese speakers), Punjab, Bengal, Odisha, Assam, Arunachal Pradesh and Nepal. Elsewhere in Asia, the Indic Solar New Year is celebrated in Myanmar, Thailand, Cambodia, Laos and southern Yunnan.

 

As the zodiacal constellation Aries (mēṣam) is held to be the first sign of the Indian zodiac, the sun’s entry into this zodiacal house marks the New Year and the beginning of the month of Cittirai (April-May), hence the New Year is called the “the auspicious day of Cittirai” (Cittirai tirunāḷ) by Tamil speakers. The New Year period coincides with meteorological and astronomical phenomena which may have determined the placement of the New Year at this time of year. It is celebrated after the vernal equinox, when the earth’s tilt is perpendicular to the angle of sunlight, hence ensuring a roughly equal day and night in both the northern and southern hemispheres. The New Year also marks the end of the northeast monsoon season (November-March) which brings much rainfall to the southeastern coast of India. It also heralds the beginning of spring (iḷavēṉil). Of the countless plants in bloom over this season, the New Year is especially associated by Tamil speakers with the konrai or the golden rain tree (Cassia fistula), a native of India and mainland Southeast Asia, which, as it name suggests, produces lush pendent yellow flowers. The 9th century Tamil Vaishnavite poet-saint Nammālvār obliquely refers to the coming of the New Year and the attendant hope of love returned by invoking the blooms of the konrai:

 

They haven’t flowered yet,

The fat konrai trees,

Nor hung out their garlands

And golden circlets

In their sensual canopy of leaves

Along the branches

Dear girl, 

Dear as the paradise of our lord

Who measured the earth

Girdled by the restless sea,

They are waiting

With buds

For the return of your lover

Once twined in your arm

 

- Nammāḻvār, Tiruviruttam 68 (trans. A.K. Ramanujan)

 

Medieval Tamil inscriptions indicate that the New Year was a large affair celebrated over a number of days. Sanskrit sources also suggest that drenching passersby with water and coloured powders was an integral part of the Indic Spring-New Year festivals, a feature which survives in the North Indian spring festival of Holi and the Solar New Year celebrations in mainland Southeast Asia. The New Year celebration among Tamil speakers is much less carnivalesque today, although this may have been a fairly recent development. J.T. Noyes, an American missionary in Jaffna describes the Tamil New Year he observed in 1851 as a “day of festivity and mirth with all classes … (who) may be seen engaged in various amusements and plays”. Surviving New Year customs among the Tamils include domestic rituals like an oil bath, wearing of new clothes, the sighting of auspicious objects in the morning and the ritual reading of the new calendar. Younger members of the family also receive gifts of money (kaivicēṭam/ kaimuḻuttam) on this day. The communal aspects of the festival include visits to the houses of friends and relatives as well as the temple where the moveable icons of the deities would be brought out in a festive procession. Kite-flying, sports activities, dance and theatrical performances rank among the public amusements held on this day. As with any festival, feasting is fundamental. Special foods for the New Year include sour and bitter dishes like pickles made out of unripe mango and neem flowers, perhaps to serve an apotropaic role or to foreground the nature of human existence which vacillates between the sweet and the pungent. 

 

Traditionally numerous eras were used to record the specific year or dating was simply based on the regnal years of a reigning king or queen. Of the eras in regular use in South and Southeast Asia, the following are notable:

 

Kaliyuga Era - 3102 BCE

Vīra-saṃvat (Jain Era) – 527 BCE (Śvetāmbara); 668 BCE (Digambara)

Buddhist Era - 544 BCE

Vikrama Era - 58 BCE 

Śaka Era - 78 CE

Gupta Era - 320 CE

Kollam Era of Malabar - 825 CE

 

The Śaka calendar beginning in 78 CE is the basis of the Indian National Calendar. Some of these calendar eras, like the Kaliyuga Era are clearly later-day developments and the starting point is entirely fictional. Each year also bears a specific name based on a 60-year cycle tabulated on the basis of Jupiter’s orbits around the sun. The 14th of April 2019 in the Gregorian calendar marks the beginning of the Indic year 5121 of the Kaliyuga Era, 2076 of the Vikrama Era and 1941 of the Saka Era. This Jovian year is dubbed Vikāri meaning the inconstant, abnormal or the changeable.

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To view video recording of Dr Muthukumaran's speech, click here.