The Fifth Trumpet took about 5 months,
Revelation 9:5, "And to them it was given
that they should not kill them, but that
they should be tormented five months:
and their torment was as the torment of
a scorpion, when he striketh a man."

The first Four Trumpets probably lasted
a few days. A lot like other judgments,
God doesn't delay, once they are poured
out, He works speedily.