When can i pray magrib salah?

In the Name of Allah, the Most Gracious, the Most Merciful.

As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.

In principle Salah must not be delayed until the last minute.

The time for Magrib Salah commences immediately after sunset and extends until the whiteness [white twilight] remains in the sky. ^{[1] [2] [3] [4] [5]}

If you pray your Magrib Salah before the Esha time sets in, your Magrib will be valid. In the inquired situation, if Esha time sets in at 8:05 pm, Magrib Salah can be performed for example till 8:04pm.

However, it is Makrooh[disliked] to delay Salah unnecessarily until the last moment. ^[6]

You may follow the perpetual Salah timetable of your area. 

And Allah Ta’āla Knows Best

Anas Sharieff Qasmi

Student Darul Iftaa

Hyderabad, India.

[1] الفتاوى ألتاتارخانياه:وآخروقتها حين تغيب الشفق ج:2 ص:٧

[2] الشامي ١/٣٦١

 [3] الهندية ١/٥١ رشيديه

[4]  حديث مسلم فيه :ووقت صلاة المغرب إذا غابت الشمس مالم يسقط الشفق ١/٢٢٣

[5]  إمداد الأحكام ١/٤١٣

[6]  فتاوى محمودية ٩/٥٥