The Saptarishis (seven sages) are the seven mind born sons of Brahma. They live for a period of time known as a manvantar (306,720,000 Earth Years). During this period of time they serve as representatives of Brahma.

At the end of a manvantara the universe gets destroyed and Saptarishis merge in God the task of filling the earth is given to new appointed Saptarishis.

Saptarishis occupy a position higher than that of all other devtas. In addition to the Saptarishis, there are other classifications of Rishis. The major classifications are Brahmarishi, Maharishi and Rajarishi

Brahmarishi :-

All the Saptarishis are Brahmarishis. The Brahmarishis are the highest class of Rishis who have understood the meaning of Brahman. Usually, one cannot rise to the level of a Brahmarishi through merit alone. Since the order was created divinely and is appointed by Lord Brahma.

However, Vishwamitra rose to the position of a Brahmarishi through his own merit alone. He performed meditation and austerities (tapasya) for tens of thousands of years and as a result he was awarded the rank of Brahmarishi by Brahma himself. Saptarishis are greater than even the devtas in power and piety.

Brahmarishis are capable to defeating all human and magical weapons. They are not influenced by the material world and the cycle of life and death or karma. They are considered as those who have understood the meaning of life and all the mysteries of creation.

Maharishi :-

Maharishi means 'great sage' in Sanskrit and refers to one who has great expanded and refined senses. Their third eye is completely open and their intuition is used to its fullest capacity. Their attention and focus encompasses the entire universe and yet they can still maintain incredibly precise detail in actions and thoughts.

Rajarishi :-

Rajarishi means 'royal sage' in Sanskrit. It refers to one who is a king or a prince as well as a sage. A Rajarishi may have left the kingship and became a Rishi such as Vishwamitra.

Manvantara / Manuvantara :-

Manvantara / Manuvantara or age of a Manu is used for astronomical period of time measurement in Hinduism. Manvantara is a Sanskrit sandhi a combination of words manu and antara, manu-antara or manvantara meaning the duration of a Manu / his life span.

Each Manvantara is created and ruled by a specific Manu who is created by Brahma. Manu creates the world and each Manvantara lasts the life time of a Manu upon whose death Brahma creates another Manu to continue the cycle of Creation. Vishnu on his part takes a new avtar and with that a new Indra and Saptarishis are appointed.

Eventually it takes 14 Manus and their respective Manvantaras to create a Kalp ( Day of Brahma ), according to the Hindu Time Cycles and Vedic time.

Thereafter, at the end of each Kalp there is a period of dissolution / Pralay where the world is destroyed and it lies in a state of rest this period is called the 'Night of Brahma'.

After that Brahma starts his cycle of creation all over again and this cycle of creation is followed by destruction lead by Lord Shiva the Hindu God of destruction.

Duration of a life cycle :-

Brahma is said to have been created from the navel of Vishnu. The life span of Brahma is of 100 years (day time). During the day Brahma starts the creation process and at night Brahma goes to sleep (only Brahma goes to sleep not Lord Shiv and Lord Vishnu) and during the night all life force he created is absorbed back into him. The creation and destruction is repeated forever.

The entire time period of the universe is known as Kalp. "Kalp" equals to one day (day + night) of Brahma. Day means the existence period of the universe and night means the destruction period of the universe. The time period of day and night is same.

In the Hindu religion Vedas were formed in the beginning of the universe. The counting of the time period of the beginning of the universe is as following.

One day of Brahma (only day) is divided into 14 parts and each part is known as Manvantara.

Manvantara 1
Manvantara 2
Manvantara 3
Manvantara 4
Manvantara 5
Manvantara 6
Manvantara 7
Manvantara 8
Manvantara 9
Manvantara 10
Manvantara 11
Manvantara 12
Manvantara 13
Manvantara 14

Each Manvantara has 71 Chaturyug. Chaturyug is combination of 4 yugs (satyug, tretayug, dwaparyug and kalyug).

One chaturyug calculation :-

Purv Sandhya
Yug Kal
Uttar Sandhya
Total Kal
One Chatur Yug Time
12,000 Years

The life span of Brahma is of 100 years. Brahma's one day is called a kalp, the creation of Brahma is called vikalp and the creation of the total creation is called mahakalp.

In the Skanda Purana, Brahma's thirty days are mentioned as :-

1) Sveta Varaha Kalp
11) Dhyana Kalp
21) Soma Kalp
2) Nilalohita Kalp
12) Sarasvata Kalp
22) Bhavana Kalp
3) Vamadeva Kalp
13) Udana Kalp
23) Supuma Kalp
4) Gathantara Kalp
14) Garuda Kalp
24) Vaikuntha Kalp
5) Raurava Kalp
15) Kaurma Kalp
25) Arcisa Kalp
6) Prana Kalp
16) Narasimha Kalp
26) Vali Kalp
7) Brhat Kalp
17) Samadhi Kalp
27) Vairaja Kalp
8) Kandarpa Kalp
18) Agneya Kalp
28) Gauri Kalp
9) Sadyata Kalp
19) Visnuja Kalp
29) Mahesvara Kalp
10) Isana Kalp
20) Saura Kalp
30) Paitr Kalp

Each day of Brahma is a duration of one thousand divya yugas. A divya yug comprises of one thousand of the four yugas. The same duration comprises his night.

Brahmas life span calculation :-

Brahmas Year
Human Years
30 days of Brahma (1 month)
259,200,000,000 human years
12 months of Brahma (1 year)
3,110,400,000,000 human years
25 years of Brahma (1 kalp)
77,760,000,000,000 human years
2 kalpas (1 parardha )
155,520,000,000,000 human years
2 parardhas (100 years of Brahma)
311,040,000,000,000 human years

The above calculation as per Vishnu Puran :-

360 days of the gods 1 year of the gods
12,000 years of the gods 4 Yugas
1,000 sets of 4 Yugas A day of Brahma
50 years of Brahma 1 Pararddham
100 years of Brahma 1 Param

According to Hindu time calculation year is used according to human years and divya years.

Human years calculation :-

Day and Night 1 Day
30 Days 1 Month
12 Months 1 Year
Divya (devta) years and Human years calculation :-
Divya Years
Human Years
Uttarayan + Dakshiyan = 1 Day
1 Year of Humans = 1 Divya Day
30 Days = 1 Month
30 Human Years = 1 Divya Month
12 Months = 1 Year
360 Human Years = 1 Divya Year

According to Bhagwat Puran at present it is Seventh Manvantara. In this 7th Manvantra it is 28th Chaturyugi going on and in this 28th Chaturyugi Satyug, Tretayug and Dwaparyug are overcand at present 4th that is Kalyug is going on.

At present it is first stage of Kalyug. The war of Mahabharat happened in the end of Dwaparyug and Lord Krishna left earth for heaven during the end of Dwaparyug. Around 5000 Years have passed since this incident and it is said that after that the Kalyug started. 5108 years have passed since the beginning of Kalyug.

6 Manvantar 1,84,03,20,000 Human Years
27 Chaturyugi 11,66,40,000 Human Years
1 Satyug 17,28,000 Human Years
1 Tretayug 12,96,000 Human Years
1 Dwaparyug 8,64,000 Human Years
1 Kalyug 4,32,000 Human Years
Total Years

Each manvantara is ruled over by a Manu. In the present Kalp, six manvantaras have already passed and the names of the six Manus who ruled were Svayambhuva, Svarochisha, Uttama, Tamasa, Raivata and Chakshusha. The name of the seventh Manu, who rules over the seventh manvantara of the present Kalp, is Vaivasvat.

The titles of the seven great sages (Saptarishis) as well as the title of Indra change from manvantara to manvantara and their gods also change.

In the present vaivasvata manvantara, the seven great sages are Atri, Vashishth, Kashyap, Gautam, Bharadvaj, Vishvamitra and Jamadagni.

The gods now are sadhyas, rudras, vishvadevas, vasus, maruts, adityas and the two ashvinis.

Mannvantara and their Saptarshis :-

First Manvantara The interval of Swayambhu Manu
Saptarshis : Mareechi, Atri, Angiras, Pulah, Kratu, Pulastya, and Vashishth.
Second Manvantara The interval of Swarochisha Manu
Saptarshis : Urja, Stambha, Prana, Dattoli, Rishabh, Nischara and Arvarívat.
Third Manvantara The interval of Auttami Manu
Saptarshis : Kaukundihi, Kurundi, Dalaya, Sankha,
Praváhita, Mita, and Sammita. (Sons of Vashishth).
Fourth Manvantara The interval of Támasa Manu
Saptarshis : Jyotirdhama, Prithu, Kavya, Chaitra, Agni, Vanaka, and Pivara.
Fifth Manvantara The interval of Raivata Manu
Saptarshis : Hirannyaroma, Vedasr, Urddhabahu, Vedabahu, Sudhaman,
Parjanya, and Mahámuni.
Sixth Manvantara The interval of Chakshusha Manu
Saptarshis : Sumedhas, Virajas, Havishmat, Uttam, Madhu, Abhináman and Sahishnnu.
The present - seventh Manvantara The interval of Vaivasvata Manu
Saptarshis : Kashyap, Atri, Vashishth, Vishvamitra, Gautam, Jamadagni and Bharadvaj.
Eighth Manvantara Savarni Manu
Saptarshis : Díptimat, Gálava, Ráma, Kripacharya, Drauni, Ved Vyás, and Rishyasringa. (Vishnu Purana: Book III: Chapter II).
Ninth Manvantara Daksa Savarni Manu
Saptarshis : Savana, Dyutimat, Bhavya, Vasu, Medhatithi, Jyotishmán and Satya.
Tenth Manvantara Brahma Savarni Manu
Saptarshis : Havishmán, Sukriti, Satya, Apámmúrtti, Nábhága, Apratimaujas and Satyaket.
Eleventh Manvantara Dharma Savarni Manu
Saptarshis : Nischara, Agnitejas, Vapushmán, Vishnu, Áruni, Havishmán, and Anagha.
Twelfth Manvantara Rudra Savarni Manu
Saptarshis : Tapaswí, Sutapas, Tapomúrtti, Taporati, Tapodhriti, Tapodyuti and Tapodhan.
Thirteenth Manvantara Raucya or Deva Savarni Manu
Saptarshis : Nirmoha, Tatwadersín, Nishprakampa, Nirutsuka, Dhritimat, Avyaya and Sutapas.
Fourteenth Manvantara Bhauta or Indra Savarni Manu
Saptarshis : Agnibáhu, Suchi, Sukra, Magadhá, Gridhra, Yukta, and Ajita.

The exact lists of Saptarishis is not perfectly known as the astral links to the hierarchy were lost.

These fourteen Manvantaras had continued in past and they would continue in the future. It is by them that a Kalp (a period of thousand Chaturyug) is completed. Calculation of time is also done through these Manvantaras.

Period of a Manvantara is slightly more then seventy one Chaturyug (all the four Yugs passing seventy one times). A Chaturyug lasts for about 3 million years while a Kalp lasts for about four thousand three hundred and twenty million years. This is equal to a day of Brahma. Brahma's night is known as Maha pralay. When that night is over Brahma again begins the work of new creation exactly as per the previous Kalpa. Carrying out this responsibility continuously for a century Brahma goes back to Bhagwad dham and his responsibilities are taken over by the next Brahma who carries out the work of creation by the inspiration of Lord Vishnu.