Short answer: In Jain tradition, Diwali (Mahavira Nirvana day) is observed on Kartik Amavasya. For 2025, the main Diwali day is commonly celebrated on October 20, 2025. Some local calendars note a two-day Amavasya span and may show October 21 as well, but most sanghs mark October 20 as the Diwali date.

Key points:

• Main Diwali day (Jain Dharma): October 20, 2025
• Amavasya timing can vary by local panchang; some calendars extend into October 21

You can read more here

Note: If you’re checking a specific temple or sangh, please refer to their local notice for exact timing.