What is the ruling on performing the 'Isha prayer an hour after the Maghrib prayer for someone who goes to sleep early for work, and is his prayer valid based on his belief that the time for 'Isha has begun at that point? And when does the time for the 'Isha prayer end, and is it permissible to perform the Shafa' and Witr prayers after the time for the Fajr prayer has begun?

The time for Isha prayer begins with the disappearance of the red twilight and ends at midnight. It is not permissible to delay it past midnight except for a valid excuse.

One must verify the entry of its time by the disappearance of redness from the horizon. One can rely on a calendar if its accuracy is known.

Prayer is not valid without an effort to know the time or reliable information from someone who knows it. The time between Maghrib and Isha ranges from an hour and a quarter to an hour and a half, varying with the seasons. It is not permissible to perform the Isha prayer before its time.