Hindu calendars and time
The Rig Veda, believed to have been written 2000 years before the common era (BCE) has possibly the oldest surviving information about Hindu time-keeping. It was later followed by the puranas and the Surya Siddhanta (loosely translated, Principles of the Sun), the Hindu astronomical text. Considering their antiquity, the math and logical thinking that went into this is impressive.
Time, in Hindu philosophy, is cyclical and infinite. Consequently time has no beginning and no end. Over the years, there have evolved several Hindu calendars. I’m going to describe one of them.
If I recall correctly, 1 Anu is the base of human-perceptible time: the time it takes for a thorn to pierce a lotus leaf. It is further divided into Param Anu’s [a.k.a Paramaanu]. So let’s start there:
3 Paramaanu’s = 1 Anu
3 Anu’s = 1 Vedha
3 Vedhas = 1 Lava
3 Lavas = 1 Nimesha
3 Nimeshas = 1 Kshana [equivalent to the 'second', although not the same value]
5 Kshanas = 1 Kaashthaa
15 Kaashthaas = 1 Laghu
15 Laghus = 1 Naadika
2 Naadikas = 1 Muhurta
30 Muhurtas = 1 Ahoraatra [equiv. 24 hours or solar day from sunrise to sunrise]
15 Ahoraatras = 1 Paksha [lunar phase]
2 Pakshas = 1 Maasa [month]
2 Maasas = 1 Ritu [equivalent to a season]
3 Ritus = 1 Ayana [a solstice i.e. movement of the sun relative to the equator]
2 Ayanas = 1 Samvatsara or Varsha [a solar year]
100 Varshas = 1 Shatabda [a century]
10 Shatabdas = 1 Sahasrabda [a millenium]
432 Sahasrabdas = 1 Yuga [an era]
Of the 4 Yugas the Kali Yuga is considered the smallest, comprising 432,000 solar years.
1 Yuga = Kali Yuga [432, 000 years]
2 Yugas = Dwapar Yuga [864, 000 years]
3 Yugas = Treta Yuga [1.296 million years]
4 Yugas = Sata Yuga or Kruta Yuga [1.728 million years]
The Hindus believe that it takes all 4 Yugas to make 1 Maha Yuga (4,320, 000 years). In terms of cyclical time, each Maha Yuga is comprised of the other Yugas in this order: first comes Sata, then Treta, then Dwapar and last comes Kali Yuga. It is believed Maha Yugas follow other Maha Yugas infinitely.
71 Maha Yugas = 1 Manvantara [period of Manu i.e. man]
14 Manvantaras = 1 Kalpa [a day in the life of Brahma]
The Hindus believe that at every Kalpa, the universe is destroyed and recreated.
According to Hindu belief, the present time (2006 CE) is in the Kali Yuga. This Yuga is believed to have begun with the death of Krishna, which corresponds to February 18, 3102 BCE. Consequently the year 2006 CE is considered to be 5106 according to this calendar. At this point you’re probably thinking, what the heck, that doesn’t add up! So, what gives? Hindu years begin with 0 (zero), not 1. The Hindu people –- a prouder people I have never known –- stake claim to inventing the zero. But, I digress. All Hindu temples and a lot of religious texts in India follow this Kali Era standard of marking time.
Although, I must add that the Kali calendar is by no means the only type of calendar in adoption. The other calendars in popular use in India are those that adhere to the Vikram Era and the Saka Era. The Vikram Era began on the day of the coronation of King Vikramaditya in 57 BCE. So this year is 2062 by that token. The Saka Era (which started when King Salivahana ascended to the throne) calendars are official Indian calendars i.e. the government recognizes that calendar and adopts it in all official literature and media. In fact, if you listen to the radio in India (specifically the All India Radio station) you’ll hear the occasional announcement informing you of the current time and date in both the Gregorian and Saka formats. So, if you’re told the year is 1927, don’t fret it.
I'm told old Hindu texts claim the concepts from the Hindu solar calendar were taken by visiting scholars and traders to Egypt (misr in Sanskrit and Hindi) from where the Romans (raumanya in Sanskrit) adopted it as basis for the Julian calendar.