Mr. Camping's Critique of Jewish Postponement Rules in 1994?

Quote from Mr. Camping's book, "1994?":

"When we attempt to use the Jewish calendar to exactly determine feast days such as the Passover and Pentecost for years other than 33 A.D., we are unable to know whether we have been given an accurate date or a date that is as much as TWO DAYS OFF. This is because the rabbis decided that the first day of Tishri, which is the feast of trumpets in the Bible or Rosh Hashanah in the Jewish calendar, MUST BE CHANGED UP TO TWO DAYS IF IT FALLS ON CERTAIN DAYS." (page 411)

Mr. Camping is referring to the Jewish "postponement rules" that the online Hebrew calendar websites operate by. He continued to cite the Jewish rules for when to change the calendar – the rules almost took up a full page. Then, he said the Jewish calendar couldn't be used unless one had a very great understanding of all the various rules. I would add, even if someone did have a very great understanding of all the rules, there is evidence that the dates arrived at are incorrect at times. His point was to show that precise and trustworthy dates cannot be arrived at by using the Jewish calendars.

Mr. Camping then proceeded to say that according to astronomical calculation we can discover precisely how accurate the Jewish calendar is.