Time of Maghrab and Isha prayer

735. Maghrib is the time that the redness in the eastern sky appearing after sunset has passed overhead.

736. Namaz of Maghrib and Isha each have special and common time:
The special time for Maghrib Namaz is from the beginning of Maghrib until the period enough for 3 Rak’at f Namaz has passed Maghrib. So, if one is passenger and offers all Isha Namaz, unintentionally in this time, his prayer is void. And the special time for Isha is the time when only period enough to offer Isha Namaz is left before mid-night and if one does not offer his Maghrib prayer intentionally, he/she must first offer Isha Namaz and after that the Maghrib Namaz.
And between the special time of Maghirb and special time of Isha, is their common time and if a person offers Isha, unintentionally, before the Maghrib and later he understands that, his prayer is in order, and he/she should offer Maghrib Namaz after that.

737. The special and common times that were mentioned above are different according to situation of people, for example, if a period enough for two Rak’ats passes from the beginning of Zuhr, the special time for Zuhr Namaz of one who is traveler is over and he is in common time, and for one who is not traveler, it must pass period enough for 4 Rak’ats from the beginning of Zuhr.

738. If a person begins Isha prayers by mistake before Maghrib prayers and realizes during the prayers that he has made an error if what he has prayed was in common time and if he has not yet gone into Ruku of the 4th Rak’at he should turn his Niyyat to Maghrib prayers and complete the prayers. Thereafter, he will offer Isha prayers. However, if he has entered Ruku of the 4th Rak’at he can continue to complete the Isha prayers and thereafter pray Maghrib; but if all that he has prayed was in the special time of Maghrib, his Namaz is void.

739. The end of time for Isha is mid-night, and as an obligatory precaution, it is necessary that for Maghrib and Isha ad the like, night is calculated from the start of sunset till Adhan of Fajr, and for night prayers and the like, it can be calculated from the start of sun shine.

740. If a person in normal circumstances does not offer Maghrib or Isha prayers till after midnight, he should, as an obligatory precaution, offer the prayers in question before the dawn prayers, without making a Niyyat of Ada (i.e. in time) or Qadha (i.e. after the lapse of time).