Jim, the website you gave does not seem to give accurate dates. Using information from well documented researchers including Issac Newton, this calender calculator seems to be two days off. Please see: http://www.johnpratt.com/items/docs/newton.html . Also this theory does not seem to line up with the fact that all Nissan 14th's were preparation days before the captivity when Israel only used the lunar/solar calendar and not the continual seven day week.
 
Jason Robillard