A period of delusion in an otherwise sane person who comes to believe that the world will end, soon, in a particularly unlikely way. In extreme cases, the deluded person may harm themselves or others out of a desire to keep them from suffering more in the event. Overall sanity will mostly return after the date comes and goes without event, but the prognosis is not good and the person should be watched further.
"Camping" after Harold Camping, who famously and wrongly predicted the end of the world on May 21st, 2011 and again on October 21st 2011.
"Trip" as in acid trip.
Alice: "I saw Charlie on the corner holding a sign saying that the the world will end next February."
Bob: "Again? I thought he learned his lesson after his last Camping trip
failed to pan out."
Alice: "Well, he says the math is REALLY correct this time..."