Think Y2K.....people will buy up and stock up. We will have the prez election, we will cautiously await and anticipate, the so-called crazies will be standing on a hilltop somewhere with outstretched arms to the heavens, the news media will hype it and stir the pot of fear, then the day will come and go as usual. Just like Y2K, nobody will remember it a year later.
Otoh, the poles may shift, or Jehovah's New City of Jerusalem may come down out of the Heavens, a comet or asteroid may strike, who knows.