Kalpa

Kalpa is a Sanskrit word ((devanāgarī: कल्प) meaning a relatively long period of time (by human calculation) in Hindu and Buddhist cosmology. The concept is first mentioned in the Mahabharata. The definition of a kalpa equalling 4.32 billion years is found in the Puranas (specifically Vishnu Purana and Bhagavata Purana).

A kalpa is a day of Brahmā, and consists of a thousand cycles of four yugas or ages.

Maha-Kalpa

Brahmā’s months are said to be 30 of his days long and his year is 12 of his months; his lifetime is said to be 100 of his years

The Maha-Kalpa embraces the whole lifetime of Brahmā, which is of 100 years (1 year are 12 of his months, which consist of 30 days each).

Further reading

• Kalpa at Theosopedia