Some believe that the times "an hour, and
a day, and a month, and a year, for to slay
the third of men", also refers to the length
of time of these angel's freedom.

This is possible, and might indicate the
remaining length of time left until the end
of the judgments on the earth.

Some judgments [not the Fifth Trumpet]
continues even after another begins.

For instance, the effects of the First Vial
are still felt when the Fifth Vial is poured
out. Revelation 16:11