What is the time for Salatul Layl (the Night Prayer) and when does it begin, and is it permissible a third or ten minutes before Fajr?

The time for the Night Vigil Prayer (Qiyam al-Layl) begins after the 'Isha prayer and ends with the emergence of true dawn (Fajr al-Sadiq). It is permissible to perform it a third of an hour or ten minutes before Fajr. The longer the prayer time, the greater the reward.