According to the Church's website, there are two 'proofs' that May 21 2011 is the judgement day. According to them, Noah's great flood occurred in the year 4990 B.C., 'exactly' 7000 years ago.
At the time, God said to Noah he had seven days before the flood would begin.
Taking a passage from 2 Peter 3:8, in which it is said a day for God is like a thousand human years, the church reasoned that seven 'days' equals 7000 human years from the time of the flood,making 2011 the year of the apocalypse.
In its second 'proof' the exact date is revealed by working forward from the exact date of the of the crucifixion - April 1, 33 AD.
According to their reasoning, there are exactly 722,500 days from April 1, 33 A.D. until May 21, 2011 - the alleged day of judgement.
This number can be represented as follows: 5 x 10 x 17 x 5 x 10 x 17 = 722,500.
The church then argues that numbers in the bible have special meanings, with the number 5 signifying atonement or redemption, the number 10 signifying 'completeness' and the number 17 equalling heaven.
'Ambassador' Sheila Jonas, another of the Family Radio faithful, spoke of her joy at joining the not-so merry band of travellers.
She said: 'I'm in it until the end.This is so serious, I can't believe I'm here.'
She will not however talk about her past because: 'There is no other story. ... we are to warn the people. Nothing else matters.'
Travelling in a convoy of five caravans, the doom-mongers are adamant that Jesus is coming in three months.
And for anyone harbouring doubts over the accuracy of the prediction, the group has a cast iron answer - 'the Bible guarantees it'.
With T-shirts and banners declaring the 'Awesome News' that Judgement Day is coming, the first convoy of five caravans set off in October last year.
They have now been joined by two other convoys, all travelling to different parts of the country spreading their message.
The oldest believer on the convoy, 75-year-old Gallegos from Utah, is similar to the rest of the church members.
In order to join the trip he had to leave behind a wife of 53 years and be away from his10 children and their families.
Others have left empty houses, sold antiques, disposed of art collections or given up cars and other expensive items to join the road trip of doom.
And as if the end of the world is not bad enough, there is one final bitter pill as we approach the apocalypse.
Apparently no one from Family Radio is sure what to do to guarantee a place in heaven.
God, they say, has already predetermined the roughly two to three percent of those who will be saved come May 21.
Sadly for the rest of us all we can do is wait until the end comes. Again.
Also covered by CNN here.