Yes, according to Jain dietary practices—especially observed by monks, nuns, and many lay followers—only boiled water is consumed, and it has strict rules regarding its preparation and timing. Typically, boiled water is prepared fresh each day after sunrise and should be consumed within a limited time (usually within 24 hours or before sunset of the same day, depending on the tradition).

The purpose of boiling water is to reduce the number of microorganisms, in alignment with the Jain principle of ahimsa (non-violence), as it minimizes harm to living beings. Drinking water that was boiled the previous day or after sunset is generally avoided to prevent the risk of new life forms developing in the water and to maintain strict discipline.

In summary:

• Only boiled (filtered) water is consumed.
• Boiled water should be prepared after sunrise.
• It should be consumed within the prescribed time (usually before sunset or within 24 hours).
• This practice reflects the Jain commitment to non-violence and purity.