Answer

In Jain practice, boiled water is generally kept only for one Prahar after cooling.

A Prahar is traditionally about 3 hours.

So, boiled water should ideally be used within about 3 hours after it cools down.

Explanation

In Jain Dharma, water is boiled to reduce harm to minute living beings present in water. But after some time, new microscopic life may again begin to develop in the water. Therefore, Jain tradition places a time limit on how long boiled water should be used.

Takeaway

For careful Jain practice, drink boiled water within one Prahar, approximately 3 hours after cooling.