The "allasso" is expected at the time of the resurrections, but most people don't know what that means.  It's the Greek word for "changed" used in 1 Cor. 15:51 and it means changed in essence, NOT changed in location.  This prognosticator thinks we'll be CHANGED in early September, but harpazo'd (changed in location) three weeks later.

Between those two changes, (he speculates) we will fulfill Matthew 24:14 which means we will be preaching the gospel of the kingdom throughout the whole world.  "And then," Jesus said, "the end will come."