Western civilization discovered deep time in the 19th century. The Vedic tradition mapped it 5,000 years ago. A Kalpa — one day of Brahmā — lasts 4.32 billion years, containing 14 Manvantaras, each 306.72 million years long. The age of the Earth: 4.5 billion years. The Vedic day of Brahmā: 4.32 billion years. The margin of error is 4%.