一增一減

A (sa) kalpa during which a human lifetime increases from ten years to 80,000 years and then decreases back to ten. At the end of the first century the increase is to 11 years; at the end of the second century to 12 years, and so on till a lifetime lasts 80,000 years; then decrease follows in the same ratio till 10 is reached. The whole period of accretion and declension covers a small (sa) kalpa, i.e. 16,800,000 years; also called 中刧.