For an in-depth look at Bill Kochman's views regarding the Two Sackcloth Witnesses, please refer to the four-part series "The Two Sackcloth Witnesses Of Revelation 11
". These two witnesses witness in the streets of Jerusalem for the full length, or 3 1/2 years -- 1,260 days or forty-two months -- of the Great Tribulation, right up to the time of Christ's Return. Here is one verse which speaks of them:
"And I will give power unto my two witnesses, and they shall prophesy a thousand two hundred and threescore days, clothed in sackcloth."
Revelation 11:3, KJV