When is the time for Fajr prayer; is it between the two adhans or after the second adhan?

The first Adhan for Fajr is sunnah to be called at night to awaken those praying (qaim) and alert those sleeping. It does not necessitate prayer nor prohibit food. As for the second Adhan, it is the one that necessitates prayer and prohibits food. The time for Fajr prayer begins after it, with the appearance of the true dawn (the horizontal white light in the horizon that is not followed by darkness), until sunrise.