Bhadrabahu in the context of "Kalpa Sūtra"

The Kalpa Sūtra (Sanskrit: कल्पसूत्र) is an important Jain scripture containing the biographies of the Tirthankaras, notably Parshvanatha and Mahavira. Ascribed to Acharya Bhadrabahu, which would place it in the 4th century BCE, it states that it was written down 980 or 993 years after the Nirvana (Moksha) of Mahavira or 1230 years after the Nirvana of Tirthankar Parswanath.