These people (Camping followers) apparently haven’t read the WHOLE Bible (or at least the part where Jesus states even He doesn’t know the exact time-and-day)..
That's because GMT hadn't been invented yet!
That are are TWO days on Earth at the present time. It's 9:33 PM Monday here in central Indiana, and 4:33 AM Tuesday in Beirut right now. There are MORE than 24 times zones around the globe.
So if someone 'predicted' something, most folks would miss it, if their clock is set local time.
(You'll note that Jesus did NOT say the YEAR or the SEASON would not be known.)
Actually though; if it's summer here, then it's winter in Rio de Janerio.
And whose YEAR will we use?
Chinese? Christian civilizations? MAYAN? <--- OOPS forget THIS one!! ;^)