Question Summary:
How many minutes before Esha is Maghreb Salaah still valid to pray?

Question Detail:

May Allah reward you for your hard work on His path and gather us in Firdaws. Aamin.My question is related to the time Maghreb salah ends. I have read (from Ta'leemul Haq) that it ends when the redness fades on the horizon.However, I would like to know: how many minutes before Isha is Maghreb salah still valid to pray?This is not to pray Maghreb at the end of its time, but I need this information in extreme cases when I cannot pray Maghreb at its beginning (because of work for example).JazaakAllahou kheyran.

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
The Maghrib salaah will be valid right up to the starting time of Isha salaah. Therefore, look at the starting time of Isha salaah on the timetable provided by ones local masjid and ensure that the Maghrib salaah has been performed before the beginning time of Isha salaah. 
Note: it is makrooh to delay the Maghrib salaah.   
And Allah Ta’āla Knows Best
Hafizurrahman Fatehmahomed 
Student Darul Iftaa
Netherlands 
Checked and Approved by,
Mufti Ebrahim Desai.