(If there has been a blog post about this already, well......too bad. I'm making another one.)
In the sneak peak of The Son of Neptune, Euryale says that Gaea will rise on the Feast of Fortune-the feast day of Roman goddess Fortuna (aka Tyche)
That day is June 11th, and the Greeks + Jason must set sail before the Solstice, and since this is before the solsitce...well...They'd better set sail weeks before it.
Percy arrives at camp two months after waking up at the Wolf House. Since we don't know exactly when that was (though I think it was around when Jason woke up at the Grand Canyon) he'll most likely be waiting a while, because I believe that the end of the book will show the Greeks arriving at Camp (though there are other possibilities as well)
Since the Feast is obviously the year after Jason and Percy switch (well, Jason anyway, since Percy isn't at Camp Rome yet,) the books will be have lots of fill-in chapters......with the whole 3-narrator-two-chapter-thing.....
Just wanted to share this little blog (even though you all probably know about it....>.<)