In Jainism, there are several reasons why many Jains avoid eating at night:

• Ahimsa (non-violence) extends to tiny creatures. Food eaten at night can contain small insects or microorganisms, and during the night these beings are more active, so avoiding night meals is seen as reducing harm.
• Purity and mental discipline. Eating at night is believed to disturb mental calm and focus, especially for those who are practicing or meditating in the evening. Keeping a clear, tranquil state of mind is valued.
• Schedule of spiritual practice. For many Jains, the daily routine includes prayers, spiritual study, and meditation in the evening. Not eating late helps maintain energy and purity for these practices.
• Varied traditions. There are differences between Digambar and Śvetāmbar practices. Some communities and individuals follow a strict rule of eating only before sunset, while others may allow eating in the early evening. The exact rule can vary by lineage, temple, and family.

If you’d like, I can share specific guidance from Digambar and Śvetāmbar traditions and point to authentic Jain texts or practices about meal timings.