According to literal dispensationalism, how does the short time of Rev. 12:12 last for 2,000 years or more?

Dispensationalism endeavors to interpret all of the Bible as literal, and attempts to assign the 1,000 years of Revelation chap. 20 to a future millennial period with a future reign of Christ on earth. See the commonly taught seven dispensation periods outlined here and here . >"Dispensationalists quibbled over the number and names of the dispensations, but most American dispensationalists followed Scofield's seven-fold scheme: Innocency (before the Fall), Conscience (Fall to the Flood), Human Government, Promise (Abraham to Moses), Law (Moses to Christ), Grace (the church age), and Kingdom (the millennium)." Summary by Timothy Webber, author of Christianity Today magazine here . However, Revelation chapter 12 opens with events that had already occurred when the book was written, specifically the birth of Christ and the birth of the church of Christ. As both of these events took place in the first century A.D., and as Rev. 12:4 depicts Satan as attempting to devour both Christ (Herod's slaughter of the children), and the saints (the persecution under Sanhedrin and Nero) in the first century A.D., how can the literal dispensationalists make the "short time" of Rev. 12:12 last for centuries? The literal dispensationalists (pre-millennial / post-millennial), as well as a few other literalists, believe the binding of Satan is yet future, that he is still "alive and well" as Hal Lindsey would say. How do they reconcile a period of 2,000 or more years since the birth of Christ and the birth of the church in the first century A.D. to the "short time" of Rev. 12:12 that the devil was permitted to try to defeat Christ?