Mahayuga

A unit of cosmic time. According to traditional Hindu reckoning, time has neither beginning nor end, but alternates
between cycles of creation and activity,
followed by cessation and quietude.
Each of these cycles lasts for 4.32 billion
years, with the active phase known as
the Day of Brahma, and the quiet phase
as the Night of Brahma. In one reckoning of cosmic time, the Day of Brahma is
divided into one thousand mahayugas
(“great cosmic ages”), each of which
lasts for 4.32 million years. Each
mahayuga is composed of four eras,
named the Krta Yuga, Treta Yuga,
Dvapara Yuga, and Kali Yuga. Each is
shorter and more evil than its predecessor; by the end of the Kali Yuga, things
have gotten so bad that the only solution is the destruction and recreation of
the earth, at which time the next Krta
Yuga begins.