Bible dates often appear to be problematic, especially by academicians who see many conflicting dates. The King's Calendar is a mathematical formula that brings dates into compliance. Scientist R.P.BenDedek's has come up with a way to synchronize the calendar.
The Jewish Calendar is very different from the Gregorian Calendar. It is based on a lunar year, so every month corresponds exactly to the moon, and is 28 days. This leaves a problem when synchronizing to seasons, and instead of having a leap year every 4th year as the Gregorian calendar does, it actually has a leap month every 3, 7, 10 years. (Actually it is much more complicated than that--hopefully you get the idea.)
The King's Calendar takes this into account these calculations, and instead of a 364 day year, it uses a 336 day year. For more info, click the link below.