Manvantara or Manuvantara, or age of a Manu , the Hindu progenitor of mankind, is anastronomical period of time measurement. Manvantara is a Sanskrit sandhi, a combination of words manu and antara, manu-antara or manvantara, literally meaning the duration of a Manu, or his life span.
Each Manvantara is created and ruled by a specific Manu, who in turn is created by Brahma, the Creator himself. Manu creates the world, and all its species during that period of time, each Manvantara lasts the lifetime of a Manu, upon whose death, Brahma creates another Manu to continue the cycle of Creation or Shristi, Vishnu on his part takes a new avtar, and also a new Indra and Saptarishis are appointed.
Eventually it takes 14 Manus and their respective Manvantaras to create a Kalpa, Aeon, or a ‘Day of Brahma’, according to the Hindu Time Cycles and also the Vedic timeline. Thereafter, at the end of each Kalpa, there is a period of dissolution or Pralaya wherein the world is destroyed and it is lies in a state of rest, during a period called the, ‘Night of Brahma’.
After that the creator, Brahma starts his cycle of creation all over again, in an endless cycle of creation followed by Destruction for which Shiva, Hindu God of destruction, and also renewal, is invoked towards the end of each such cycle.
Duration of a Manvantara
The actual duration of a Manavantara, according to the Vishnu Purana is seventy one times, the number of years contained in the four Yugas, with some additional years, adding up to 852,000 divine years, or 306,720,000 human years (Vishnu Purana). Here the division of time which they measure, Seven Rishis, certain (secondary) divinities, Indra, Manu, and the kings, his sons, are created and perish at one period and the interval is called a Manvantara. It is equal to seventy-one times the number of years contained in the four Yugas, with some additional years: this is the duration of the Manu, the (attendant) divinities, and the rest, which is equal to 852.000 divine years, or to 306.720.000 years of mortals, independent of the additional period. Fourteen times this period constitutes a Bráhma day that is, a day of Brahmá; the term (Bráhma) being the derivative form. The Brahma’s life span is 100 Brahma varshas. The following table will illustrate clearly the link to our years and Brahma years.
Sub-divisions
1 human year – 1 Ahoratra for God (1 day and 1 night)
360 Ahoratras of Gods – 1 Deva Vatsara
12,000 Deva Vatsaras – 1 Chaturyuga (36, 00,000 years of human beings)
(4800 Divya Vatsaras of Kritayuga, 3600 Divya Vatsaras of Treta Yuga, 2400 Divya Vatsaras of Dvapara Yuga, & 1200 Divya Vatsaras of Kali Yuga)
71 Chaturyugas – 1 Manvantara (1 life span of Manu)
14 Manvantaras – 1 Kalpa (1 day of Brahma)
2 Kalpas – 1 day and night of Brahma (Ahoratra)
360 days of Brahma – 1 Brahma Varsha
100 Brahma Varsha – 1 life span of Brahma.
Manus of the Śveta Vārāha Kalpa
First Manvantara – the interval of Swayambhu Manu
Saptarishis (सप्तर्षि): Marichi, Atri, Angiras, Pulaha, Kratu, Pulastya, and Vashishtha.
Beginning of Creation
Dhruva Episode
Descent of the Lord as Half-man-half-lion to bless Prahlada
Second Manvantara – the interval of Swarochisha Manu
Urja, Stambha, Prańa, Dattoli, Rishabha, Nischara, and Arvarívat.
The Episode of King Suratha
Third Manvantara – the interval of Auttami Manu
Sons of Vashishtha: Kaukundihi, Kurundi, Dalaya, Śankha, Praváhita, Mita, and Sammita.
Fourth Manvantara – the interval of Támasa Manu
Jyotirdhama, Prithu, Kavya, Chaitra, Agni, Vanaka, and Pivara.
The Episode of Gajendra, the elephant-devotee
Fifth Manvantara – the interval of Raivata Manu
Hirannyaroma, Vedasrí, Urddhabahu, Vedabahu, Sudhaman, Parjanya, and Mahámuni.
Sixth Manvantara – the interval of Chakshusha Manu
Sumedhas, Virajas, Havishmat, Uttama, Madhu, Abhináman, and Sahishnnu.
The churning of the Ocean of milk
Seventh Manvantara (the present) – the interval of Vaivasvata Manu
Kashyapa, Atri, Vashishtha, Vishvamitra, Gautama, Jamadagni, Bharadvaja.
We are in the 7th Manvantara .Each Manvantara is divided into 71 Maha-Yugas.
We are presently in the kaliyuga of the 28th maha-yuga of the 7th manvantara of Brahma’s day
Each Maha-yuga is divided into 4 Yugas, namely, Sata Yuga or Kritha Yuga (4x*), Treta Yuga (3x*) (Descent of Lord Rama), Dwapara Yuga (2x*) (Descent of Lord Krishna) and Kali Yuga (*)
Note: *=4, 32,000Years
Eighth Manvantara (Future) – Saavarni Manu
Díptimat, Gálava, Ráma, Kripa, Drauńi, Vyása, and Rishyasringa.
The next Manu (i.e., the eighth) will be Saavarni. This promise was made by Mother Goddess to one King Suratha during the second Manvantara. To him (and another) the triple story of Mother Goddess is narrated in the Devi-bhagavatam (also Chandi or Durga-saptasati ). The story begins from a mythological event that happened after the end of the last Kalpa (day of Brahma) and ends up by forecasting the feats of Mother Goddess that are yet to happen in this Kalpa. One such is the prediction that Suratha will be born as Manu Saavarni.
Ninth Manvantara – Daksa Savarni Manu
Savana, Dyutimat, Bhavya, Vasu, Medhatithi, Jyotishmán, and Satya.
Tenth Manvantara – Brahma Savarni Manu
Havishmán, Sukriti, Satya, Apámmúrtti, Nábhága, Apratimaujas, and Satyaket.
Eleventh Manvantara – Dharma Savarni Manu
Niśchara, Agnitejas, Vapushmán, Vishńu, Áruni, Havishmán, and Anagha.
Twelfth Manvantara – Rudra Savarni Manu
Tapaswí, Sutapas, Tapomúrtti, Taporati, Tapodhriti, Tapodyuti, and Tapodhan.
Thirteenth Manvantara – Raucya or Deva Savarni Manu
Nirmoha, Tatwadersín, Nishprakampa, Nirutsuka, Dhritimat, Avyaya, and Sutapas.
Fourteenth Manvantara – Bhauta or Indra Savarni Manu
Agnibáhu, Śuchi, Śukra, Magadhá, Gridhra, Yukta, and Ajita.
JYOTHISHI 
