At the beginning of Ramesh Menon’s translation of The Ramayana he includes this note:
Three hundred sixty-five human years make one year of the Devas and Pitrs, the Gods and the manes.
Four are the ages in the land of Bharata – the krita, the treta, the dwarpa, and the kali. The krita yuga lasts 4,800 divine years, the treta 3,600 years the dwarpa 2,400 and the kali 1,200; and then another krita yuga begins.
The krita or satya yugas the age of purity; it is sinless. Dharma, righteousness, is perfect and walks on the four feet in the krita. But in the treta yuga, adharma, evil, enters the world and the very fabric of time begins to decay. Finally, the kali yuga, the fourth age, is almost entirely corrupt, with dharma barely surviving, hobbling on one foot.
A chaturyuga, a cycle of four ages, is twelve thousand divine years, of 365 times 12,000 human years long. Seventy-one chaturyugas make a manvantara; fourteen manvantaras, a kalpa. A kalpa of a thousand chaturyugas, twelve million divine years, is one day of Brahma, the Creator.
Eight thousand Brahma years make one Brahma yuga; a thousand Brahma yugas make a savana; and Brahma’s life is 3,003 savanas long.
One day of Mahavishnu is the lifetime of Brahma.
This understanding of time and the Universe seems to suit me.