When Dr. Heribert Illig published his theory that 297 phantom years were inserted into AD-reckoning between 31 August 614 and 1 Sept. 911, this was refuted by Dr. Ulrich Voigt (Hamburg) on the ground that the proper succession of weekdays would have been affected by such a manoeuvre.

At first I supported Illig by proving that weekdays did succeed in the regular fashion: The last day before the interval was a Saturday; the first day of the "secure" AD day-count was a Sunday. Thus no break can be detected.

Now, after roughly ten years of continuous discussion with various opponents I see my error and admit that Voigt has the better argument. Voigt insists that Illig's 297 years must not only be divided by 7 in order to maintain the normal sequence of weekdays but by 4 as well, or rather by 7 times 4 = 28. If the total amount of phantom years is not divisible by 28, there must sooner or later - in this case in the third year already - arise discrepancies between weekdays after inserting the phantom years. This is mathematically correct and disproves Illig's thesis of 297 phantom years.

Without diving into the whole discussion all over again I shall shortly explain my new way of arguing and where my error came up.

It is well known that weekdays follow equal dates in a rhythm that might be called "Jacobinic"; that is after every 11, 6, 5 and again 6 years. That is why the sequence is not broken even if the total sum is not divisible by 28. The inserted amount of 297 years corresponds to 10 times 28 (=280) plus 11 plus 6. "In this case", I wrote in 1996 in Illig's review, "it still has to be ascertained whether the sequence (11-6-5-6) follows suit after the inserted interval." Lacking possibilities and mathematical skill, I had to leave it to others to verify the proposal.

Now I followed the simple and clever argument of Voigt in his book (2003) and thought it through all over again, understanding that the Jacobinic sequence before the phantom period (614) had been 11-6-5-6 and after it (911) went on 5-6-11-6 thus breaking up the correct order of the weekdays, although this did not appear as such at first sight.

As far as computist manoeuvres are concerned, the break in the order of weekdays might seem irrelevant. But other nations used the Julian Calendar with its strict observance of weekdays and leap years, as well, and could not be forced by the emperor or the pope into following any new rhythm. They in fact preserve the same system until now and therefore the insertion of an odd number of years not divisible by 28 is an impossibility.
Voigt further pertains that the sequence of Christian Easter is another equally important factor to be regarded when judging the sum of phantom years. So the Metonic cycle (19 years) has to be another factor, bringing the whole sum up to 532 years (28 multiplied by 19). This therefore would be the smallest possible amount of years that could be artificially inserted.

Although this argument is equally valid in mathematical terms it has no backing from "outside" as no Christian nations can prove an uninterrupted sequence of Easter throughout medieval church history. Therefore this argument only holds within the Catholic frame of historiography.

Basically I repeat what I have insisted on for many years (see 2001, p.151) that the thesis of Illig concerning the insertion of 297 years is a mere game of computists and has no chance of historical reality.

Moreover, Voigt's book (2003) gives strong indications that our whole AD counting is based on Easter cycles and is not bound to historical events. Latest findings of Voigt will be presented by him in speeches on Oct. 30 in Hamburg and on Dec. 4, 2006, in Berlin. A book to that effect is planned by him for next year.

For anyone not totally informed on the theory of phantom time reckoning the following postscript has to be added: The refutation of the sum of 297 years does not mean that other parts of chronology criticism would have to be abandoned; missing archaeological proof for several centuries - as well as the discovery that AD time reckoning is a late and fragile construction and not supported by historical records - are sustained with even more vigour and on better grounds.

References

Illig, Heribert (1996): "Das erfundene Mittelalter" (Econ, Düsseldorf)
Topper, Uwe (1999): "Erfundene Geschichte" (Herbig, München)
(2001): "Fälschungen der Geschichte" (Herbig, München)
Voigt, Ulrich (2000): "Zeitensprünge und Kalenderrechnung" (in ZS 2/2000, S. 296-309)
(2003): Das Jahr im Kopf (Likanas, Hamburg)
(2005): "Über die christliche Jahreszählung" with comments by K.-H. Lewin, Andreas Birken and Heribert Illig (in ZS 2/2005, S. 420-481)