Apart from Landa’s manuscript, page 66 of the “Chronicle of Oxkutzcab” provides a series of double dates. Thompson corrected the errors in the text, some of these corrections are unproblematic but here we focus on the problematic “corrections”. There are differences in the haab coefficients in the text and those of the Classic period in the Petén area. Some of the dates in the list correspond to the Puuc Year-Bearer conventions but not all. Thompson assumes that deviations from the Puuc convention are errors. Hence, he shifts all dates into the same set. Aldana argues that Thompson “invokes the one-day shift between Puuc dates and Classic period dates to move them back into their Classic period ‘equivalents’. Thus 13 Ahau [Ajaw] 7 Xul becomes 13 Ahau [Ajaw] 8 Xul” (p 28).

However, Thompson neglects the progression within the manuscript itself. It is not necessary to have a static one-day shift, but at least two or three shifts. In the sequence of 13 years mentioned in the chronicle there are three sets of coefficients represented. Aldana wonders if this could be an indication that the Maya actually had a leap year as mentioned by Landa. That is a possibility but “Thompson reduces the entire data set to a single data point: 13 Ajaw 8 Xul occurred in 1540” (p 28-29).

There are no katuns mentioned in the manuscript but Thompson assumes that 13 Ajaw 8 Xul also was the end of a katun. Since he follows the “continuity hypothesis” he argues that this date corresponds to the Long Count date 11.16.0.0.0.

Thompson makes another move to allow continuity between the Chronicle of Oxkutzcab and the Landa equation. He changes the Christian years to correspond to the beginnings of the Maya years, rather than the endings. Hence he changes the supposed 13 Ajaw 8 Xul katun to 1539 instead of 1540 which is the actual recorded date in the chronicle (well, there it is actually 13 Ajaw 7 Xul). Basically, Thompson argues that Juan Xiu (the author of the chronicle) knew that the New Year 11 Ix 1 Pop and the “katun” end/beginning 13 Ajaw 8 Xul occurred in 1539 but since the Year Bearer (11 Ix) ended in 1540, Xiu assigned both dates to 1540. This is a move that is necessary for the GMT correlation but “it masks an argument that Thompson cannot really convince even himself of” (p 29).

Aldana writes that “if 13 Ajaw 7 Xul was in 1540 – that is, if we were to take the record as written – and 11 Ix was the Year Bearer at the time, then 12 K’an 1 Pop (Landa’s date) would have to have occurred in July of 1554, *not* in 1553” (p 29). Thompson needs to provide an internally inconsistent analysis of the Oxkutzcab manuscript for it to be continuous with the Landa equation. Thompson’s argument becomes circular since “his interpretation of Landa depends on his interpretation of the Oxkutzcab manuscript, but his interpretation of the Oxkutzcab manuscript is dependent on his interpretation of Landa” (p 30). Thompson has created a closed system that has been black-boxed ever since. To be continued…