I love these post-rapture stories that start off claiming that the problem was that Camping's math was incorrect! No! No! No! The problem is that the entire story is wrong. Take a fairy story to start with and inject some numerology into it and it can't get any more wrong! And you want to try to add precision to that by taking into account leap seconds? Puh-leeze people!
There's no rapture - except for the story that helps sell all those fantasy books. Because in the end, it's all about having a good story to tell so they keep coming back for more.
BTW, there's no Bilbo Baggins either.