Hindu measurement of Time
One month for humans is one day for the ancestors (pitri).
Shuklapaksha is the lunar fortnight during which the moon waxes and krishnapaksha is the lunar fortnight during which the moon wanes.
Shuklapaksha corresponds to night for the ancestors and krishnapaksha corresponds to day. Thus, thirty human months are merely one month for the ancestors. Three hundred and sixty human months are one year for the ancesotrs.
One human year is one divaratara for the gods.
The human year is divided into two ayanas, each consisting of six months. These are known as uttarayana and dakshinayana. Uttarayana is day for the gods and dakshinayana is night.
Thirty human years are one month for the gods and three hundred and sixty human years are one year for the gods.
Time is divided into four yugas (eras). These are known as satya yuga or krita yuga, treta yuga, dvapara yuga and kali yuga. The lengths of these yugas are defined in terms of years of the gods.
Satya yuga has four thousand years of the gods, treta yuga three thousand, dvapara yuga two thousand and kali yuga one thousand.
A cycle of satya yuga, treta yuga, dvapara yuga and kali yuga is known as a mahayuga. Thus, a mahayuga would seem to consist of ten thousand years of the gods. But this is not quite correct. In between any two yugas are intervening periods, known as sandhyamshas. For example, the sandhyamsha for satya yuga is four hundred years, for treta yuga three hundred years, for dvapara yuga two hundred years and for kali yuga one hundred years. Once one adds the sandhyamshas, a mahayuga adds up to twelve thousand years of the gods.
A little over seventy-one yugas constitute one manvantara. Fourteen such manvantaras are one kalpa. A kalpa is merely one day for Brahma. At the end of Brahma’s day, the universe is destroyed. It is then created afresh when a new day dawns for Brahma.
The Characteristics of the Yugas as one progressively moves down the scale from satya yuga to kali yuga, the power of righteous diminishes and evil starts to triumph. In treta yuga people were righteous. The system of varnashrama dharma goes back to treta yuga. This is typified in the principle of four varnas (classes) and four ashramas (stages of life). The four varnas are brhamanas, kshatriyas, vaishyas and shudras. Each class has its proper place, each its assigned occupations as determined by the principles of division of labour.
The four ashramas are brhamacharya (celibate studenthood). Garhasthya (householder stage), vanaprastha (forest-dwelling stage and sannyasa (hermithood).
Everyone followed the tenets of varnashrama dharma in treta yuga. Individuals were equally handsome and equally wealthy. Poverty and disease were unknown. The weather was clement and, initialy, there was no need to build houses. Cities and villages were not known. People lived freely in the mountains and on the shores of the oceans. But as people became evil, the weather turned inclement. Houses had to built so the people might be protected from the heat and the cold. Cities and villages were planned and constructed.
Evil became even more prevalent in dvapara yuga. In some cases, individuals began to practice that which was against the dictates of varnashrama dharma. To bring men back to the righteous path, the knowledge of the sacred Vedas had to be disseminated amongst humans. To this end, the great Vedavyasa divided the Vedas into four. Various other shastras (sacred texts) were also composed in dvapara yuga. These include ayurveda (medicine), jyotisha (astronomy) and arthashastra (economics). Hatred, jealousy, warfare and other evils first originated in dvapara yuga. Individuals did not stick to their own classes while marrying, and cross-breeds started to be born. But some remnants of righteousness could still be found, so that average life expectancies amounted to two thousand years.
Kali yuga is the worst of the four eras. Theft, hatred, falsehood, fraudulence and egotism become the norm. As a natural corollary to such evils, drought and famine recur again and again. Even the brahmanas are led astray. They do not study the Vedas, nor do they perform yajnas. The brahmanas degenerate so much that they mix with shudras. As for the shudras, they become kings. Shudras even start to study the Vedas. Evil always has its effect. Disease becomes rampant and life expectancies go down.
OM NAMO NARAYANAYA