The Hindu concept of time is extremely vast and divided into yugas and mahayugas. They are calculated as follows:
One human year represents one day for the divine.
360 divine days make one divine year.
12,000 divine years make one mahayuga.
One mahayuga is divided into 4 yugas, which are called; Krita, Treta, Dwapar and Kali
In terms of Human year :
Kali yuga = 432,000 years
Dwapar yuga = 864,000 year ( dwa means twice)
Treta yuga = 1,296,000 year ( tre means thrice)
Krita yuga = 1,728,000 years ( 4 times Kali yuga)
Hence one complete mahayuga is equal to 4,320,000 ( 4.3 million ) human years.
The following are considered the ruling gods in each of the four yugas.
Kali yuga Sri srinivasa
Dwapar yuga Sri Krishna
Treta yuga Sri Rama
Krita yuga Sri Rangnatha
Seventy two mahayugas constitutes one Manavantara (i.e. Life of Manu) such 14 Manavantara one day of Brahma. This works out to 4.35 billion human years ( 72 x 14 x 4.32 million ). At present according to panchang, in 2008 according to Georgion calander, the universe is it is 1,955,885,109 years old.
Brahma's whole day is 8.70 billion human year ( 1 day of 4.35 billion year & 1 night of 4.35 billion human year ). such one year of Brahma will be 8.7 billion x 30 days x 12 months = 3.132 trillion human year. Brahma is supposed to live 100 such years which works out to 313.2 trillion human year. This is called Param & half of this called Para Ardhan.
Message to all readers :-
From this we have to understand that our life is not as long as even an eye blink & hence we should do maximum possible self less work for entire mankind suffering from various problems in this world. Every human being is god creation. If we can any way help them anyway to our capacity, it will be the real work for which we are born. If we start using even 10% of our income for income generation of any one poor family, then also it is a big work & our last time of life will give us gratest satisfaction in our heart that atleast we have done some work for someone without any self interest.
I personally believe that to give food to someone is merely relief activity. But if we give a small machine of even 1000$ value, then it is a tool for life time food / livelihood to a family. Oh.. god we want to see entire mankind of this world happy. Pls...inspire us what can we do...