In Jainism, Chauvihar refers to the practice of refraining from any food or water intake after sunset until the next morning. Navkarsi is the practice of taking food or water only after 48 minutes (one prahar) after sunrise.

If you have not observed Chauvihar (i.e., you have consumed food or water after sunset), the spiritual purity associated with Navkarsi the next day is considered to be compromised. According to Jain conduct, Navkarsi should ideally be performed only if Chauvihar has been observed the previous evening.

If, due to unavoidable circumstances, you could not do Chauvihar, it is best to maintain a minimum period of fasting from water and food before performing Navkarsi. According to Jain texts and traditional practice, at least 9 hours should lapse between your last intake of water/food and Navkarsi. However, this is a secondary rule; the ideal remains to observe Chauvihar.

Summary:

• If Chauvihar was not done, ensure a gap of at least 9 hours from your last food/water intake before Navkarsi.
• For full adherence to Jain conduct, always try to observe Chauvihar for a proper Navkarsi the next day.

It’s best to consult your Jain guru or local Jain community for specific guidance, as practices can vary by tradition (Murtipujak, Sthanakvasi, Terapanthi, etc.).