What is the time period for each prayer?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

Each prayer has its own particular time at which it must be performed. Allah Says (what means): {Indeed, prayer has been decreed upon the believers a decree of specified times.} [Quran 4:103]

The Prophet has clarified when the time of each prayer starts and when it ends. So anybody who prays a given prayer before its fixed time or after it, his prayer is invalid unless there is an excuse accepted by the Sharee’ah for doing so. Here is a summary of the specified times.

The Thuhr prayer begins when the sun passes its meridian and it continues until an object's shadow becomes as long as the length of the object itself. The time of ‘Asr begins just after Thuhr until the sun sets. The time of Maghrib begins with the disappearance of the sun and lasts until the red twilight ends. As for the time of ‘Isha, it starts when the red twilight disappears and continues until one third of the night has passed. It can also be prayed anytime before Fajr if there is a necessity for the delay. The time of Fajr starts with the true dawn and lasts until the sun rises. So, these are the times specific to each prayer. But if you cannot define them, you could return to an Islamic agenda specifying the times of the prayer or just pray in your mosque and be confident in your Muaththin (the person who calls for the prayer) and Imam. We remind you that what is important is the beginning of the specified time of the prayer.

So, the person might sometimes pray before the Athaan in his mosque because he is certain that the specific time of that prayer has started.

For more benefit on the times of the prayer, please refer to Fatwa 82253.

Allah knows best.