Hindu cosmology imagined the universe in billions of years — while every other ancient culture counted in thousands.
A kalpa (one day of Brahmā) = 4.32 billion years, derived from a mahāyuga of 4,320,000 years multiplied by 1,000.
— Manu Smṛti 1.68–73; Bhāgavata Purāṇa 3.11
Earth is ~4.54 billion years old; the universe ~13.8 billion.
A genuine, defensible parallel.
Almost every ancient cosmology imagined a young world a few thousand years old. Hindu time is the dramatic exception: it counts in yugas, kalpas and the lifespan of Brahmā, reaching numbers in the billions and trillions of years. A single day of Brahmā — a kalpa — works out to 4.32 billion years, which is startlingly close to the actual age of the Earth (4.54 billion). It is a wonderful coincidence of scale.
But honesty matters: these numbers were not measured. They come from a numerological scheme — a mahāyuga of 4,320,000 years (itself built from ratios of 4:3:2:1 for the four yugas) scaled up by factors of a thousand. The match with geology is an artefact of choosing very large round numbers, not evidence that anyone dated rocks. What is genuinely remarkable is the *imagination*: a civilisation comfortable contemplating cyclic, near-eternal time when everyone else thought in generations.