I'm writing a paper on the "Phantom Time Hypothesis". You can Google this, or refer to this paper by Niemitz http://www.cl.cam.ac.uk/~mgk25/volatile/Niemitz-1997.pdf
, or this by Illig http://www.bearfabrique.org/Catastrophism/illig_paper.htm
, or this article about it on the BBC website http://www.bbc.co.uk/dna/h2g2/classic/A84012040
. Briefly, the hypothesis is that in order to reconcile the difference between the Julian and Gregorian calendar, we have to remove 300 years from the 'official' calendar. Illig reckons these years would be 614-911. Thus many popes, emperors, wars &c never existed. The hypothesis explains this as a massive conspiracy. The entire history of that period was invented by Holy Roman Emperor Otto III, whose conventional dates are given as 980 –1002, but who really lived 300 years before that, from about 680 to 702. However, in connivance with Pope Sylvester II, he decided to convince everybody they were living at the end of the First Millennium, because it was a wonderful opportunity for positive PR, and Otto liked the idea of reigning in the Year 1000. “It was such a nice, round number”. He changed the dates, and got scribes to write an extra 300 years of history.
I have my own ideas about this but welcome the thoughts of people here. In particular, I am interested in how ordinary people in the early middle ages actually recorded years. Did they really rely on priests to tell them the time (it is essential to the hypothesis that the whole Church was involved in the conspiracy)? Or did they record dates and years in their own way? How often did official documents record the exact date?
My only knowledge of reference to dates is Bede, who includes a whole chronology of the world in his book on the English Church and people. (However, Bede was living right in the middle of the 'phantom period' so perhaps his works were a later forgery).