When making qunut for calamities, when does the imam stop the qunut?

Question:
The question says: A number of mosque imams are in a state of confusion regarding the calamities occurring in these days, specifically concerning the cessation of the calamity. Do they expect it to end, or do they continue with the calamity? And how is the cessation of the calamity determined?

Answer:
The cessation of the calamity: if they know that the calamity has ended, the qunut ends, if they know that. And if they do not know, the default is that the calamity remains, until they know that it has ceased or until it becomes predominant in their minds that it has ceased.