The prayer is not valid; because it is a condition for the validity of the prayer to believe that the time has entered; so that it becomes an act of worship with a decisive intention; because the doubter is not decisive, so the prayer is not valid from him; because when he ruled the invalidity of his prayer based on a legal evidence which is his caution, it does not become valid if the opposite appears. See: Al-Maraqi, p. 215.