^17:12"And the ten horns which you saw are ten kings, who have not yet received a kingdom, but they receive authority as kings with the beast for one hour.

"And the ten HORNS which you saw are ten KINGS, who have not yet received a KINGDOM,

Was this what Daniel saw (Daniel 7:1-7-11)?

"who have not yet received a KINGDOM" could be interpreted as:

1. during John's lifetime
2. until the tribulation period
3. until the brief "loosing" of the Devil (Revelation 20:7-10)
4. without geopolitical boundaries but nonetheless an operational unit.

but they receive AUTHORITY as KINGS with the BEAST for one hour.

If you take the Daniel 9:27 one week as the seven years of tribulation as most scholars do, then this one hour is roughly 15 days. On the other hand, if you take 2 Peter 3:8-13, then we have a time range of a hundred of a second to 41+ days. Given these large time conversion differences, many scholars take this to mean for a brief period of time.

Due to the precision of time in the rest of the Revelation, this probably is a literal one hour. The 9/11/2001 initial acts took place within one hour so this is plausible. One cannot be sure how long one hour is, though, at this time in the tribulation given the "time changes" that may have occurred during earlier judgments (for example, the fourth trumpet in Revelation 8:12).