Is it permissible to pray Fajr a few minutes before sunrise, around 6:15 AM, given the difficulty of waking up at 5:00 AM and then going back to sleep?

Delaying Fajr prayer until al-Isfar (clear light) without a valid excuse is considered unlawful (haram) by some scholars and disliked (makruh) by others, especially if it occurs after the light has spread across the earth. Delaying it until after sunrise without a valid excuse is not permissible under any circumstances. However, delaying the prayer due to sleep, after having taken measures to wake up, incurs no sin. Performing the prayer at the beginning of its prescribed time is among the best deeds.