The Elements Used in the Computation of Time



The main element used is the Sun itself. One solar day is the time taken by

the earth to rotate around its own axis. One solar day is made up of 24

solar hours, one solar hour is sixty minutes and one minute is sixty

seconds.

The time taken by Sol to make a circuit of the Zodiac from the First Point

of the Sidereal Zodiac is called a Sidereal Year. This is 365.25363 solar

days. A Tropical Year is the time taken by the Sun to make a circuit of the

Tropical Zodiac This is 365.242194 solar days.

The Five Types of Years

There are five types of years

1) Solar Year

2) Jupiterian Year

3) Savana Year

4) Lunar Year

5) Sideral Year

Solar Year

The time taken by Sol ( Sun ) to cross one degree is called a solar day.

When the Sun crosses from one Sign to another, this is called Surya Sankrama

( transit to another sign ). The time taken from one Surya Sankrama to

another is called one solar month. The motion of the Sun is fastest at the

first week of January and is slowest at the first week of July. In other

words, since the Sun's motion is fastest in the Vedic months of Sagittarius

and Capricorn, it takes only 29 days for the Sun to traverse 30 degrees of

Sag and Cap. Conversely, it takes 32 days for Sol to traverse 30 degrees of

Cancer, since his motion is slowest at Apogee, in the Vedic month of Cancer.

Jupiterian Year ( Barhaspathya )

One Barhaspathya is time taken by Jove ( Jupiter ) to traverse 30 degrees of

a sign. The duration is 361 days and a Jupiterian Cycle is roughly 12 years.

Savana Year

One Savana day is reckoned from Sunrise to Sunrise. 30 such Savana day is

called one Savana month. 360 such days is one Savana year.

Lunar Year

A lunar month is the time calculated from one New Moon to the next New Moon.

Since during a solar year, 12 Full Moon were visible , the Zodiac was

divided into 12 constellations. 12 Lunar months constitute one Lunar Year.

This is 354.367 days. This is 11 days less than the solar year.

Sidereal Year

One sidereal day is time taken by Luna to traverse a constellation of 13

degrees and 20 minutes. The Moon takes 27.3 days to revolve around the

earth. 27.3*12 is one Sidereal Year and it is 327.6 days.

Apparent Solar Day ( Savana Dina )

The time taken by the earth to rotate around its own axis. From a geocentric

perspective, the Sun moves one degree per day.

Sidereal Day ( Nakshatra Dina )

This is the time taken by the earth to rotate around its own axis with

regard to Sidereus, the constellation of fixed stars. This is 23 hours and

56 mins and 4.0953 seconds.

An apparent Solar Day is 24 hours. According to Indian Astronomy, a solar

day is 60 Nadis. 60 Vinadis is one Nadi ( Nazhika ) and 60 Tatparas is one

Vinadi. There are minuter subdivisions like Pratatparas ( 60 Pratatparas

constitute one Tatpara ), corresponding to micro seconds and nano seconds in

Western time calculations. 2 and a half Nadis is one hour or 24 minutes is

one Nadi.

While as per Western calculations, a day is reckoned from midnight to

midnight, an Indian day is reckoned from sunrise to sunrise and a Hijra day

is calculated from sunset to sunset.

Sidereal Solar Year

The time taken by the Sun ( from a geocentric perspective ), to make a

circuit of the Sidereal Zodiac . This is 365 days, 6 hours 9 minutes and 9.8

seconds.