Shooting off fireworks before it's actually dark is a form of premature ejaculation. Discuss...
It speaks to the violent-prone, alcoholic prone celebrants...who don't mind the wildness, the angst and the borderline insanity of the act of "shooting off fireworks".
I found a good cartoon on the topic, here on Agnostic.com
Some of us have to go to bed to wake up at 4am for work. If we don't blow them off now, we lose our shot.