In Jain cosmology, a purva is a very large time unit.

• 1 purvāṅga = 84,00,000 years
• 1 purva = 84,00,000 × 84,00,000 years = 70,56,000,000,000,000 years (70.56 trillion years)

This is a traditional scale used in Jain texts to describe cosmic time. Both Śvetāmbara and Digambara traditions use this large unit with the same idea; the numerical way of presenting it may vary slightly by text, but the meaning remains the same.

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