Kalyanak on Chaitra Vad Chaudas is not a standard or common date for Mahavir Janma Kalyanak. Chaudas (the 14th day) is simply a tithi, while Mahavir Janma Kalyanak is traditionally observed on the 13th day of the bright half of Chaitra (Chaitra Sud 13) in the Jain lunar calendar. In other words, the birth anniversary of Mahavir is typically on Chaitra Sud 13, not on Chaudas.

Key points:

• Chaudas = 14th day of the bright/dark half, but it is not the usual day for Mahavir’s Janma Kalyanak.
• Mahavir Janma Kalyanak is commonly celebrated on Chaitra Sud 13 (the Veer Teras in some calendars), with puja, palna-ji (cradle ceremony) night vigils, and related observances.
• Digambar and Shwetambar traditions both recognize the 13th of Chaitra Sud for Mahavir’s birth, though local calendars may show slight variations.

If you’re looking for a JainKnowledge page that discusses Mahavir Janma Kalyanak and its typical tithi, you can read more here