All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Whoever misses offering the funeral prayer until the dead is buried may pray at the grave, and there is no difference in this regard between a relative and others.
The scholars differed in opinion about the duration that is allowed to perform the funeral prayer after the burial. The view that we adopt in Islamweb is that it extends to one month and this is the view of most scholars as stated by Ibn Qudaamah in his book entitled Al-Mughni.
Allah Knows best.