What is the ruling on the prayer of someone who discovered after a period of time that their 'Isha and Fajr prayers were performed before their prescribed times, and must they make up the prayers they performed for a month and a half based on this calendar? And what is the ruling on the prayer of someone who relied on several different calendars?

If a Muslim prays Fajr or Isha before their prescribed time, which is determined by the legal signs, then their prayer is not valid and they must repeat it, because the entry of the time is a condition for the prayer's validity. As for differences in calendars, one must act according to the later time when there is a discrepancy. Calendars are relied upon if they are supervised by trustworthy people. The questioner is advised not to pay attention to obsessive thoughts regarding these matters.