This is an excellent and nuanced question, as practices can differ among Jain sects and traditions, but the underlying principle is always ahimsa (non-violence toward even the smallest life forms).

Scriptural and Traditional Basis:

• The strictest guidance, especially during periods of heightened spiritual discipline like Paryushan or Chaturmas, is to consume boiled water (ukāḷūṁ pāṇī) within one prahar (approximately 3 hours) of boiling. This is to minimize the risk of new life forms (micro-organisms) developing in the water, which would increase the possibility of himsa if consumed.

- This guidance is found in the conduct literature of the Jain Agamas (e.g., Ācārāṅga Sūtra, Dasavaikālika Sūtra) and is emphasized in pravachans by Jain Acharyas, especially for those observing upvas (fasting) or ekasana (one meal a day). - Many Murtipujak Shvetambar and Digambar Jains, especially monks and nuns, strictly follow the 3-hour (one prahar) rule.

• In the general daily practice for lay Jains (shravaks and shravikas), a more lenient rule is sometimes followed, where boiled water may be consumed within 24 hours, provided it is stored properly and not exposed to the possibility of new organisms (e.g., by keeping it covered and in a clean container). This is more common outside of special observances like Paryushan.

• Some Sthanakvasi and Terapanthi sects are even stricter, sometimes recommending 6 or 12 hours as the maximum time, especially in hot climates where microorganisms multiply faster.

Summary Table:

| Occasion | Maximum Time for Boiled Water (Traditionally) | |------------------------------|----------------------------------------------| | Paryushan, Upvas/Ekasana | 3 hours (one prahar) | | Everyday (Some sects) | 24 hours (if stored properly) | | Strict sects/Hot weather | 6 or 12 hours |

Which is correct?

• 3 hours (one prahar) is the stricter, scripturally emphasized guideline for periods of heightened spiritual practice (Paryushan, Chaturmas, Upvas).
• 24 hours is a more relaxed, contemporary adaptation for daily lay practice in some communities.
• Follow the practice taught by your tradition, guru, or local Jain Sangh; but during Paryushan, the 3-hour rule is most widely respected for minimizing himsa.

References:

• Jain Agamas (Ācārāṅga Sūtra, Dasavaikālika Sūtra)
• Pravachans of Acharyas during Paryushan
• Jain conduct literature (Charitra Granthas)
• Practical guidance from Jain Sanghs and traditions

In summary: During Paryushan and fasting, the correct practice is to use boiled water within 3 hours (one prahar) of boiling, as per Jain scriptures and tradition. For everyday use, some allow up to 24 hours, but the stricter 3-hour rule is preferred during auspicious or disciplined periods.