Hindu time calculations.

sadgurupAdukA jayathI
With the arrival of the new (vikruthi) year, it seems as if people are contemplating the indications that lie for the year ahead! It seems to be a popular topic as I have been asked about the upcoming year and its charecteristics, predictions, more context of the year cycles etc by different members of this group during different conversations over the last 2 or 3 days. In this post I will mention a little bit about the qualities and the features of this year and also shed a bit of light on the hindu idea of time and creation. Be warned that the topic is vast and technical, and I am only shedding minor light on this here as it is beyond my abilities to go into greater detail.

First things first! Prior to looking at the year at hand it is apt to see the context. So we will start (like with everything) at the begenning.
According to our dharmA (the vEdic cosmology), creation is cyclic in nature. ''srishti: sthUlikaranam'' - i.e. creation is merely grossification (of something that already 'exists', albeit in a subtle and imperceptible, formless form). With this concept in mind we will need to see the idea of creation. Thus we have a creation for which there is no begenning (anAdhI) and to which there is no end (anantaH). One which 'appears' and 'disappears', one which is 'revealed' and 'veiled' periodically in a cyclic manner. As we all know, the hindu creator is known as Brahma. This Brahma is the one tasked with srishtI or the act of making tangible and manifest the universe(s). The exact method of bringing forth this phenomenal world is another tangent and one beyond the scope of this discussion and for fear of moving away from the main topic at hand and of elaborating this post to a great degree, I will refrain from digression.

This Brahma is, though the creator, still bound by the limits of time. The allocated life span of Brahma is 100 BrahmA years. To understand the immense nature of the time scale of BrahmA, we need to go from the ground up - i.e. from our own human perspective!

The full life span allotted to the human (in kali yugA) is 100 years. Some ancient texts of AyurvEdA and certain schools hold this to be 120 years and this is known as pUrnAyu or full/whole life span. The older systems of calculating time were based on the lunar progressions and thus one human year (samvatsarA) can be understood as 12 lunar months (mAsAs). A lunar month consists of approximately 29.5 days and is divided into 2 pakshAs or segments - the shukla pakshA (waxing/bright half) and the krishna pakshA (waning/dark half). Each pakshA consists of 15 thithIs (prathipad or prathamI to amAvasyA or pUrnimA). A thithI or lunar day can be defined as the time taken for the longitudinal angle between the moon and the sun to increase by 12 degrees. Thus there are roughly 360 days in a lunar year.

The solar measurements as elucidated to stunning detail in the sUrya siddhAntA, is slightly different. Around the time of its publication (some say around 2 century AD), the Romans and the Babylonians were already using a Julian or sun based calendar. The day is composed of 24 hours and each hour is further divided into 60 equal parts called minutes. The minute itself is further divided into 60 equal parts called seconds. The second, thus was the smallest division of time. In the sUrya siddhAntA however, an even more minute division of time is shown.
Counting from a respriration (prAnA), we have the following. 6 respirations make a vinAdi and 60 vinAdIs make one nAdi. In tamil this is known as nAzhigai. 60 such nAdis make one sidereal day(i.e day and night = 24hrs). There are also other systems of calculation of time -
One paramAnus (the interval of blinking) = 4 seconds (approx).
One vighatI = 6 paramAnus (i.e. 24 seconds approx)
One ghatI = 60 vighatIs (i.e. 24 minutes approx)
One muhUrtA = 2 ghatIs (i.e. 48 minutes approx)
One nakshatra ahOratram (one sidereal day) = 30 muhUrtAs (i.e. 1440 minutes or 24 hrs)

30 days = 1 month
6 months = 1 ayanA (there are 2 ayanAs in the year - uttarAyanA (northerly) and dakshinAyanA (southerly))
2 ayanAs = 1 year.

The purAnAs and the vEdA offer an even more minute understanding of time. Though we do not use such miniscule measures on a daily basis, they are revealed in the scriptures. Starting from a trasarEnu (extremely subtle) which is said to be the combination of 6 celestial atoms! The time that is needed to integrate 6 such trasarEnus is known as truti ( 1/1687.5th of a second!!) These measures are way smaller than even a nimEshA or the time taken for a blink of an eye. As 100 trutis make one vEdhA. 3 vEdhAs make one lavA. 3 lavAs make one nimEshA or the blink of an eye!And so on to make the full period of a day. Anyway, I digress.....

One human year that is made of 2 ayanAs is equal to one day(incl night) of the dEvAs or the celestial beings. That is, one ayanA is the day and the second ayanA is the night. The time of the dEvAs(celestials) and the asurAs (their 'darker' cousins) is mutually oppossed - i.e. day for dEvAs is night for asurAs and night for dEvAs is day for asurAs.
30 such dEvA days make one dEvA month (much like our own!). So we have now on this time scale - 30 human years = one dEvA month. 12 such dEvA months make one dEvA year or divine year. Which if we calculate, is equal to (30X12 = 360 human years). The life span of the dEvAs is 100 dEvA years. Which in human time is 360 X 100 or 36,000 human years.

Next in order, we can see the description of yugAs (roughly translated as epochs?). The hindu system reveals that there are 4 yugAs, which proceed in a cyclic fashion. They are
satya yugA or krita yugA
trEtA yugA
dwApara yugA
kali yugA
These four yugAs are not equal - i.e. their duration is varied. The first yugA known as satya yugA is the longest period and as it proceeds the time span of each yugA gets lesser and lesser. We will next see how many years these yugAs are composed of -
satya yugA = 4800 dEvA varshAs or dEvA years = 17,28,000 human years.
trEtA yugA = 3600 dEvA years = 12,96,000 human years.
dwApara yugA = 2400 dEvA years = 8,64,000 human years.
kali yugA = 1200 dEvA years = 4,32,000 human years.
One cycle of these four yugAs is known as one chaturyugA or mahAyugA. Thus, we see that
one chaturyugA = 12,000 divine years = 43,20,000 human years!

In the bagawad gItA, we see the statement ''"sahasra-yuga paryantam ahar-yad brahmano viduh", - which reveals that 1000 mahAyugAs/ chaturyugAs is one day of brahmA. In more simpler (if such a thing is possible!) terms - we have seen above that 4.32 million human years makes one chaturyugA. So with 1000 such chaturyugAs we will have 4.32 billion human years (432 thousand crore) to be one day of brahmA. This period is known as kalpA. brahmA's night is also of the same duration as his day. So we can see that 2 kalpAs (i.e. 864 thousand crore human years) is one sidereal day of brahmA.
2 kalpAs = 1 day (and night) of brahmA = 2,40,00,000 dEvA years = 2,40,00,000 X 360 human years
30 brahmA days = 1 brahmA month = 259.2 billion human years.
12 brahmA months = 1 brahmA year = 3.1104 trillion human years.
brahmAs full life span is 100 brahmA years. This period of 100 brahmA years is divided into 2 parArdhAs of 50 brahmA years each.
100 brahmA years (the life span of brahmA) = 311.04 trillion human years!!

Now coming back to the time called kalpA, which is one day of brahmA - the creation/manifestation of the universe begins at the dawn of brahmAs day and culminates at the start of brahmAs night. The universe is veiled or dissolved during the period of his night. So for one kalpA the world is manifest and for the same period (1 kalpA) the universe lies dissolved. The next morning of brahmA He goes about the business of creating/revealing the universes again.....and so on for 100 brahmA years.

1 kalpA = 1 day of brahmA = 1000 chaturyugAs = 1,20,00,000 dEvA years = 4.32 billion human years.
This day of brahmA is divided into 10,000 parts known as charanAs and we can see that satya yugA has 4 charanAs, trEtA has 3, dwAparA has 2 and kali has 1 charanA.
71 chaturyugAs (or cycles of the above mentioned 4 yugAs) = 1 manvantarA .
Each manvantrA is ruled by a manU. During his 1 day brahmA creates 14 such manUs, who rule the 14 manvantrAs in each kalpA.
At the end of each manvantrA (71 chaturyugAs) we have something known as sandhi kAlA. This period of time known as sandhi kAlA is of the same duration as on satya yugA (4800 dEvA varshAs or dEvA years = 17,28,000 human years). During this period of time, the earth lies submerged in water and is brought forth yet again at the end of the sandhi kAlA. There is also something else known as Adi sandhi which is also equal to 17,28,000 human years which occurs at the begenning of the kalpA.

So we now have the kalpA which consists of - 1X Adi sandhi + 14 manvantrAs + 14 sandhIs
kalpA = 14 manvantarAs + 15 sandhIs (each composed of 4 charanAs)
kalpA = 994 chaturyugAs + 60 charanAs = 994 chaturyugAs + 6 X 10 charanAs (note each chaturyugA has 10 charanAs)
kalpA = 994 chaturyugAs + 6 chaturyugAs = 1000 chaturyugAs.

Now that the vast context of time is set, we can proceed to see our present position in this frame. Those of you who have paid some attention to the mantrA in the samkalpA (shubhE shObanE.....) will be able to realise what those terms like shwEtavarAha kalpE etc mean!!
Our current brahmA is 50 years old (50 brahmA years) already. Meaning 50 brahmA years out of his allotted 100 have already elapsed. We are currently in the first day of his 51st year. (refer - dwitIya parArdhE, meaning 2nd parArdhA where we have already seen 1 parArdha = 50 brahmA years). The current day of brahmA (i.e. current kalpA) is known as shwEtavarAha kalpA (refer - shwEtavarAha kalpE). Within this one day of brahmA, the rule of 6 manUs has already elapsed (we saw before that each kalpA has 14 manUs, who each rule for a period known as manvantrA), and we are now in the period of rule of the 7th manU who is known as vaivasvathA. So this seventh manvantrA is known as vaivasvatha manvantrA (refer . vaivasvatha manvantrE) . Within this particular manvantrA the period equal to 27 chaturyugAs (i.e. full cycles of all 4 yugAs) has already elapsed and in the 28th chaturyugA the satya, trEtA and dwApara yugAs have also elapsed. Thus we are currently in the kali yugA period of the 28th chaturyugA (refer. ashtAvimshadadimE kaliyugE). According to the experts in such calculations this current kali yugA began in the year 3012 BC (in the julian system of numbering), on the midnight of the 18th of febraury.

Thus we have that 5112 years have already passed in the current kali yugA and the 5113 rd year in kali has just been born. And if we were to do the sums to calculate the age of the current brahmA in human years :
3.1104 trillion human years = 1 brahmA year
155.52 trillion human years = 50 brahmA years (which have elapsed)
1.973 billion human years = 6 manvantrAs already past including the relevant sandhi kAlAs of this current kalpA/day.
116.640000 million human years = 27 chaturyugAs that have also elapsed in the current manvantrA.
3.888 million human years = the 3 yugAs that have already elapsed in the current chaturyugA (the 28th).
5112 human years = the time elapsed since the birth of the current kali yugA.
So the current age of the present brahmA = 155.52 trillion human years!!

In case your head is reeling from all this complicated math, I leave you with something to cheer you up.
According to our sAstrAs, there is simply no end to the worlds. We are in effect immortal - really! And as we saw before 1 kali yugA has 4,32,000 human years and we are only a mere 5112 years gone into it. So there are 4,26,888 human years before even a temporary end of the world while we switch to the next yugA in the current manvantrA. Even our current manU (the 7th one of 14 such manUs), has only exhausted 27 and with the end of this current yugA, will have exhausted 28 chaturyugAs out of his allotted 71 - so that leaves us 43 more chaturyugAs under the same manU vaivasvathA, before a long sandhI period where the earth will stay submerged in water until the birth of the next manvantrA. Then we have 7 more manUs to go only within this day (kalpA) of brahmA!! After a similarly long night of brahmA, we will proceed to the 2nd day of our current brahmAs 51st year.....and then the 3rd day and so on. Finally,after almost another 155.52 trillion human years this present brahmAs time of 100 years will be up. That means nothing to you and me, as after this brahmA there will simply be another brahmA who will also live 100 brahmA years and we'll be back again to enjoy the fruits of our accumulated karmA!!
The next time you wish for eternity - please think! It really is a long long time!