We have a military fort nearby that used to shoot off canons every now and then, in the middle of the night. It was weird and I have no idea why they would practice such a loud activity at such an unreasonable hour.
We're near a military airfield, nobody
likes flying in the nights very much, but it
has to be done to some extent for practice, I presume. (And I guess that the designers of military airplanes would have a good laugh if you were to suggest modern low-noise (passenger plane) jet engines.
)
But
artillery? Unless you have some very special nighttime winds ... and even
then, AFAIK it'ld just be doing the math somewhat differently, no need to
fire the thing ... hmm, any chance they believe there's some
actual enemies they need to shoot at? ???