I would state Rev 11 is a sign that can't be mistaken. If anyone in those days has even a shred of faith and love for God they will believe those signs. As a loving God warns and warns upfront. 1260 days of testimony and the two witnesses who are killed by the beast and refused burial, (the beast is now in the world or false prophet who acts in behalf of the angel of the abyss), are raised up to life and caught up to heaven in full view as the whole world looks on. Now that the beast is in the world and the last signs have been given by God the great tribulation will begin. The Lord and His armies are the ones who kill the beast as Jesus suddenly appears on the last day or His 2nd coming. The great battle of God almighty. Rev 16:15What are we to be watching for?
Since the beasts reign is only 42 months then from the witnesses being killed and raised to life and the return of the Lord has to be less than 4 years.
Until those signs take place no one (not even the Son) knows the day or hour of the 2nd coming of the Lord and the resurrection of the saints.
Rev 11 must take place or be fulfilled before the 2nd coming.
FYI I don't hold to a pretrib rapture. I do hold that when the Lord appears (2nd coming) those that are left alive will be caught up into the air so that they too may be clothed with their new bodies not made of the dust of the earth.
R.