Further details of the book appear in a review in the California Chronicle:

"Temple at the Center of Time" discusses the significance of the number 33. For instance, 33% of [I think he means "or" - RB] one third of an hour is 19 minutes and 48 seconds. Yes, 1948...

Unless you want one third of an hour, which gives you twenty seconds, but that wouldn't fit.

...Amazing also is Avebury Circle..."The latitude of the Avebury Circle was established with such precision that it underscores the importance of '2520' as key to the circle's intended message...If 2,520 years are counted forward from the fall of Babylon in 539 B.C. and the 33 years that Christ walked the Earth are subtracted, the year is A.D. 1948, the rebirth of Israel.

This is all in a grand tradition of crackpot interpretations of ancient monuments; significantly, WorldNetDaily has also promoted the pseudo-science of pyramidology.

However, the WND piece fails to note how all this fits into Flynn's wider theories, or to tell us much about him at all. A short bio appears on this site:

In 1991 after completing his education at Carroll College in Montana, David Flynn created the "watcher Website" combining his background in Theology and Clinical Psychology in the research of biblical ufology. David's website is a repository for research dealing with UFOs, the Monuments of Cydonia on Mars, Angels, Aliens & End Time Prophecy. David has written popular articles on Mars and of the Biblical significance of the Cydonian Monuments. His decidedly alternative views on Cydonia were presented on the television programs "Strange Universe", and the PAX TV's -"Encounters with the Unexplained: What is Really on Mars," which explored the meaning behind the Pyramids and Sphinx-face found in NASA images of the surface of Cydonia Mars. David's Flynn's new book discusses knowledge that was previously known only by the highest ranking members of Mystery Schools.

Another site calls him "a well known crypto-archaeologist in the Christian community". Some of his ideas are laid out on his own website. One essay he appears particularly proud of is "An Occult Translation of the Roswell Event: Count down to 2012", where he tells us that

It is significant that the United States recovered the debris and "alien" bodies of the Roswell crash on the 4th of July 1947. America itself was founded on the same date in 1776. This year was chosen by the occult elite behind the formation of America for a special reason.

888 is the sum of the letters of the letters in Greek of the name Jesus (each Greek letter represents a number). A second "messiah" (888) plus the first messiah (888) = 1776...We know that 33 degrees of earth's circumference is 2012 miles and that 33 is a prominent number in the Roswell message. 33 is also prominently featured in the location of the first descent of angelic forces to Mt. Hermon. Might this numeric connection indicate a similar type event occurring in the year 2012?...

However, while this silliness is mostly all good fun, the references to "Mystery Schools" and an "occult elite" show that Flynn is also tapping into the kind of darker conspiracy-mongering seen in the likes of John Hagee. Here's another essay, entitled "Babylon Revisited":

In America's modern colleges, though there are 360 degrees in a complete circle, a student's four years of intellectual labor and thousands of dollars produce only the graduation of one degree. This accomplishment earns the student a Bacchus laurel, for this is really what "bachelor" means. Bacchus is the Roman version of Dionysus, Greek god of wine revelry and facades, lies, and drunkenness.

During the ritual of graduation, the degree candidate wears a symbolic hat--a mortarboard. The mortarboard represents the common person's function in a world system controlled by the occult elite, to carry the cement for building to the stonemasons...The academic system of the West was designed by the occult elite from the beginning, and it is still under their control. The highest members of the "occult Brotherhood" past and present consider themselves graduates of 33 degrees. It would not be possible to acquire 33 degrees through the academic institutions of Europe and America in one lifetime. Only through the membership in the secret fraternal institutions of the occult can 33 degrees be obtained.

One point that struck me: America was founded in 1776 due to an "occult elite", yet Israel was founded in 1948 presumably due to God's plan (as with Christian Zionism). But what's to prevent someone from tweaking this so that 1948 is also the result of a conspiracy? As with David Icke, John Hagee, Pat Robertson, and others who go down this road of seeing secret patterns in history, the potential for anti-Semitism remains, whatever their own intentions. This essay by Chip Berlet provides some useful context.

Earlier this year WND carried an attack on the Bible Literacy Project. The BLP is a syllabus for studying the Bible in schools, looking at historical context and drawing on the work of serious Biblical and literary scholars. But while WND objects to a historical-critical look at the Bible, a man who uses the Bible to create a bizarre mash of paranoia and fantasy that has absolutely no respect for the intended meanings of the Biblical text apparently deserves a puff piece.

One blogger casts a sceptical eye over Flynn's ideas here.