Chovihar in Jain Dharma means not eating or drinking after sunset and before sunrise.

It is a form of careful restraint followed mainly to protect ahimsa and avoid harm to very small living beings that may be present in darkness.

In simple words:

• No food after sunset
• No water after sunset
• No food before sunrise
• No water before sunrise

Why it is followed:

• To reduce violence to living beings
• To maintain discipline and self-control
• To support purity in sadhana and vrat

In Jain practice:

Chovihar is especially observed by many Shravaks and Shravikas as a strict vow or discipline, and it is also deeply respected in muni life.

If you want, I can also explain:

• Chovihar vs Tivihar
• Why water is avoided after sunset
• How chovihar is practiced in daily Jain life