Diwali in Jainism is Mahavira’s Nirvana Day. It is a time to remember Mahavira’s moksha and to light the inner lamp of knowledge.

Key points:

• The main Jain observance is on Kartik Amavasya (the new moon night in the Kartik month). In 2025, the commonly observed day is October 20, 2025. Some local calendars may show October 21 due to clock/panchang differences, but many sanghs mark October 20 as the Diwali date. ( jainknowledge.com)
• Digambar and Śvetāmbara traditions may note small differences in the exact tithi (e.g., Digambar often associates Nirvana with Kartik Krishna 13, Śvetāmbara with Kartik Krishna 14 in some calendars). The spiritual meaning remains the same: Moksha of Mahavira and the shining of true knowledge. ( jainknowledge.com)

What to do (simple home puja common to Jain practice):

• Light a diya and offer flowers or simple lamp-light to honor Mahavira and other Tirthankaras.
• Recite Namokar Mantra or a short Jain prayer; spend a moment in reflection or up-puja (a brief devotion).
• If you wish, read a small portion of a Jain scripture or listen to a short teaching about Mahavira’s keval jnana.
• If appropriate for your tradition, you may also perform a short samayik (mindful quiet) or pratikraman during the period.

Note: Some Jains also perform a light, peaceful observance similar to the broader Diwali period, but the key focus remains Mahavira’s Nirvana and inner light. For guidance aligned to your local sangh, check your temple calendar.

You can read more here