THIS IS WHEN THE BIBLE SAYS THE TWO WITNESSES ARE KILLED WITHOUT DOUBT........

In order to determine when the two witnesses are killed, we must first find the timing of their deaths in context with the timing of other Scriptural events.  We know that  God calls them to heaven 3 1/2 days after they are killed according to:

Revelation  11:12-15

"And they heard a great voice from heaven saying, Come up hither,  and they ascended up to heaven in a cloud........And the SEVENTH ANGEL SOUNDED ; and there were great voices in  heaven saying, The kingdoms of this world have become the kingdoms of our Lord, and of His Christ and He shall reign forever and ever." 

SO, THERE YOU HAVE IT:

The two witnesses are killed and ascend to heaven JUST PRIOR TO THE SEVENTH ANGEL , WHO IS THE LAST ANGEL, SOUNDING HIS TRUMPET  ANNOUNCING THE SECOND COMING OF THE LORD JESUS CHRIST TO RECLAIM HIS  OWNERSHIP OF THE EARTH. The very NEXT EVENT  AFTER the two witnesses are killed and ascend to heaven is the seventh and last angel of the great tribulation judgments sounding his trumpet which means THE TWO WITNESSES ARE KILLED AT THE END OF THE GREAT TRIVBULATION according to the Scriptures. 

According to Your Holy Word, come Lord Jesus !