Reckoning of time amongst the pitrs (ancestors)
- 1 human fortnight (14 days) = 1 day of the pitrs
- 30 days of the pitrs = 1 month of the pitrs = (14 x 30 = 420 human days)
- 12 months of the pitrs = 1 year of the pitrs = (12 months of pitrs x 420 human days = 5040 human days)
- The lifespan of the pitrs is 100 years of the pitrs (= 36,000 pitr days = 504,000 human days)
Reckoning of time amongst the Devas.
- 1 human year = 1 day of the Devas.
- 30 days of the Devas = 1 month of the Devas. (= 30 human years)
- 12 months of the Devas = 1 year of the Devas = 1 divine year (= 360 human years)
- The lifespan of the Devas is 100 years of the Devas (= 36,000 human years)
The Vishnu Purana Time measurement section of the Vishnu Purana Book I Chapter III explains the above as follows:
- 2 Ayanas (six month periods, see above) = 1 human year or 1 day of the devas
- 4,000 + 400 + 400 = 4,800 divine years (= 1,728,000 human years) = 1 Krita Yuga
- 3,000 + 300 + 300 = 3,600 divine years (= 1,296,000 human years) = 1 Tretá Yuga
- 2,000 + 200 + 200 = 2,400 divine years (= 864,000 human years) = 1 Dwápara Yuga
- 1,000 + 100 + 100 = 1,200 divine years (= 432,000 human years) = 1 Kali Yuga
- 12,000 divine year = 4 Yugas (= 4,320,000 human years) = 1 Mahayuga (also called divine yuga)
Reckoning of time for Brahma.
- 1000 Mahayugas = 1 kalpa = 1 day (day only) of Brahma
(Two kalpas constitute a day and night of Brahma)
- 30 days of Brahma = 1 month of Brahma (259.2 billion human years)
- 12 months of Brahma = 1 year of Brahma (3.1104 trillion human years)
- 50 years of Brahma = 1 Pararddha
- 2 parardhas = 100 years of Brahma = 1 Para = 1 Mahakalpa (the lifespan of Brahma)(311.04 trillion human years)