Such events don't seem to fit the style with which God acts in this age. Of course there are still outright miracles, and, for that matter, there are still demonic possessions, but for the most part, God seems to want people to decide to accept or reject Him based on more subtle evidences, such as the witness of Christians living ordinary lives in holiness [at which we too often fail], the wonders of the created universe, the course of history, etc., rather than based on spectacle. I suspect this flows from the same reason as the Ascension: if Christ were still physically and visibly on earth, there would be less merit in believing in Him and more fault in disbelieving in Him.
"A wicked and adulterous generation seeketh after a sign," and our generation is certainly wicked and adulterous enough for that. Be that as it may, one of the DeMille-esqe signs involves Three Days of Darkness, despite the prediction's dubious history.
But prophecy usually takes a spiritual perspective, so that things that really have eternal significance are presented in ways that seem to call for special effects. Could that be what's going on here? Outside of historical accounts (like the three days Christ spent in the tomb, counting part of Good Friday and part of Easter Sunday), an expression like "three days" likely means a short, but not negligible, period of time; it could easily mean a few decades. As for darkness, what could that be but the inability to see, the inability to understand what is in front of us, and the fear and confusion that go along with that?
As I have said before, it looks like a spiritual neutron bomb has been detonated over us. The point of a neutron bomb was that it left buildings standing, but killed off the life inside them; in a similar way, we see institutions like the Boy Scouts continue on, but with their souls destroyed. Could it be that the mystics were right, and that for refusing one too many opportunities to repent, we have been handed over to a short period of darkness in which we, as a society, will find the truth impossible to believe and incredible foolishness compelling?
The darkness is certainly here. It's the "short time" part that concerns me.