Short answer: If 5:00 am is before sunrise where you live, it’s better not to boil then. In Jain practice, using fire in darkness is avoided to prevent himsa of night‑active beings.

Simple, practical way:

• Boil the water in daylight (after sunrise and before sunset), ideally the previous day.
• Filter with a clean, tightly woven cloth or chhannu.
• Cool, cover, and store in a clean vessel. Carry it to school in the morning.
• Try to use it within a day. Do not keep re‑boiling the same water.

Tradition notes:

• Both Shvetambar and Digambar traditions encourage preparing drinking water in daylight only.
• Monks follow a strict “daylight‑prepared, limited‑time use” rule; householders follow the same spirit as far as possible.