History of the Catholic Church and its calendar

[War Arrow]

As probably mentioned in some of my posts, I've been putting the Central Mexican calendar through the wringer these last couple of months, just trying to get the thing to work. Anyway thanks to the Mighty Force of Professor Gordon Brotherston (author of Feather Crown) - with whom I've since been in contact on this subject - I've sort of done it and arrived at the same stumbling block that GB says has been "haunting" him for many years. Put simply, the whole thing spins upon a correlation of 3 dates as being equivalent to one another:
August 13 1521 (Spanish Julian calendar)
1-Coatl (Mexican Tonalpohualli calendar)
F1.7.20 - last day of Miccailhuitontli (Mexican Xiuhpohualli calendar)
The problem is that in order for the Mexican calendar to work, one of these must be wrong. I've tried every possible permutation (and believe me, there's plenty) and can only conclude that it's the Julian date. Oddly enough, August 13 Gregorian is actually August 3rd Julian (and keep in mind that this was 61 years prior to calendar reform, so anticipation of said reform seems unlikely) and once you slot August 3rd Julian into the equation - the entire Mesoamerican calendar lights up like a bonfire and suddenly everything makes sense. Given the mathematical elegance of the Mexican calendar, and the simple fact that these people were no dummies when it came to calculating the finer points of solar and even sidereal time - it looks rather bad for August 13th as the supposed date upon which Tenochtitlan surrendered to the Spanish - yet this date was widely recorded.
August 13th is the feast day of St. Hippolytus who was remembered as being holy to the point of extremism, and if indeed the conquest was recorded as ending on a different day to that upon which it fell according to indigenous records, I can only imagine theological reasons as the point - stamping a mythic structure on one's victory etc.
Perhaps it's improbable, but at present it's the best idea I've got, so my question is this:

Anyone here know of any incident in which the Catholic church is known to have fiddled the books and made a slight adjustment to a particular recorded date for whatever reason?

I'm not saying that August 13th is wrong and the conquest really and definitively did end on August 3rd, but at the present it really is the one weak link in the chain and so is therefore under suspicion.

[Minimalist]

Dionysius Exiguus messed up the BC/AD calculations by 5 years. Does that halp you?

[Digit]

How about the most obvious WA, a slip of the pen? I'm retired and the only time a day or date matters to me if CSI is on TV or I've got an appointment, how often have you had to look at a newspaper, or what ever, to check the date?
A hospital appointment for me some time ago gave Tuesday as the day and Thursday as the date, and that's with calendars, digital watches, the net etc freely available to us.

[War Arrow]

How about the most obvious WA, a slip of the pen? I'm retired and the only time a day or date matters to me if CSI is on TV or I've got an appointment, how often have you had to look at a newspaper, or what ever, to check the date?
A hospital appointment for me some time ago gave Tuesday as the day and Thursday as the date, and that's with calendars, digital watches, the net etc freely available to us.

Well, of 600ish European eye-witnesses the great majority would have been more focused on the long, drawn-out siege, and not all would have been literate (I imagine) leaving us with Cortes' letters to the King of Spain and to the best of my knowledge, not much else. Of the ideas I've got, the slip of the pen seems the most likely - not that there aren't plenty of arguments against it, but it seems possible and doesn't require any sort of conspiracy theory to support it. Problem with all of this is whatever hypothesis there may be, its all beyond the scope of testing so far as I can tell.
Need a break I think.
Last few days I've woken up and the potential significance of St. Hippolytus (whose feast day is August 13th) is the first thing to come into my head.

[Forum Monk]

I'm having difficulty following the problem WA. If Aug 13 Gregorian = Aug 3 Julian and the latter date works, why doesn't the former???

I'm sure you understand there was a 10 day adjustment to align the Gregorian calendar to a 21 Mar equinox since the Julian calendar had slipped. I am also sure, I guess, you understand the differences between Julian and Gregorian and the tropical year. I may be able to help if I understood the prblem better.

[War Arrow]

Because it isn't August 13th Gregorian. It was August 13 1521 - 62 years prior to Gregorian reform reaching Mexico. The problem is that Aug 13 Jul correlated with the indigenous dates 1-Coatl and 20-Miccailhuitontli produces a Mexican calendar which basically doesn't work as it shifts equinox dates out by 10 days (and yes, I know what the figure of 10 days looks like) amongst other problems. Replace Aug 13 Jul with Aug 3 Jul and 1-Coatl / 20-Miccailhuitontli work perfectly. So basically someone somewhere appears to have lied about a date. I appreciate the offer but I've been up to my armpits in this stuff for the last month and am painfully well acquainted with the mechanics of Gregorian calendar reform.

The essence of the problem is that it basically looks as though someone recorded a Gregorian date, 62 years prior to reform, which obviously didn't happen, which is why I was wondering whether anyone knew of a precedent for a Catholic culture getting a date wrong. In other words I'm just weighing up the probabilities because this seems to be one instance where if the indigenous date was falsified it would have shown up in the form of an inconsistency within the Mexican calendar as a whole (it being mathematically very complex).

The problem is also that it's difficult communicating exactly what's wrong in succinct form. I've written at length on this. I can post my long droning essay here if it'll help.

Oh sod it.

The Tonalpohualli in Solar Time

Being the shorter of the two cycles, the Tonalpohualli count repeats with greater frequency within the Xiuhpohualli year. The first day of each new Tonalpohualli count will therefore necessarily occur on a different day of each consecutive Xiuhpohualli year, and often one Xiuhpohualli year may contain the tail end of one Tonalpohualli, then the next cycle in its entirety, then terminate just after the beginning of a third cycle. One analogy made earlier in this narrative likened the interaction of teteton and day-signs to a pair of cogged wheels with varying numbers of teeth. Returning to this analogy, the Tonalpohualli and Xiuhpohualli might be imagined as two much larger wheels, one with 260 teeth, the other with 365. These larger wheels must turn many times before resuming their original alignment which, in terms of the calendar as a whole, amounts to fifty-two years; that is, it takes fifty-two years for the Tonalpohualli count to reoccupy the same group of 260 solar days upon which it began fifty-two years earlier. This large cycle amounts to the fifty-two years defined as one Xiuhmolpilli.
The year is named after the Tonalpohualli configuration of teteton and day-sign which falls upon the year-bearer day of the Xiuhpohualli calendar. Owing to the mathematical framework involved, all thirteen numerals, but only four of the twenty day-signs can occupy this day (these being the series III group referred to earlier: Acatl, Tecpatl, Calli, and Tochtli) so as each year draws to its end, each year-bearer day forges a different combination of teteton and day-sign resulting in a progressive sequence of named years: Ome Acatl (Two Reed), Yei Tecpatl (Three Knife), Nahui Calli (Four House), Macuilli Tochtli (Five Rabbit), Chicoce Acatl (Six Reed), Chicome Tecpatl (Seven Knife) and so on. After fifty-two years, the calendar will have cycled through all possible configurations of four day-signs and thirteen teteton, following which the sequence returns to its beginning at the start of a new Xiuhmolpilli. Whilst this may seem a complex system, the mathematics are surprisingly simple. The calculations regarding which Tonalpohualli day constitutes each new year-bearer are only a variation on those by which the first day of 2006 was a Sunday, that of 2007 was a Monday, and that of 2008 will be a Tuesday.
Many attempts have been made to correlate the Tonalpohualli count with the Xiuhpohualli calendar and with frequently questionable results, and it seems that most of these problems may arise from a single inaccurate date. A great number of accounts attribute Cuautemoc's surrender to Hernan Cortés to the 13th of August, 1521, a date equivalent to Ce Coatl in the Tonalpohualli count and F1.7.20 in the Xiuhpohualli - the last day of Miccailhuitontli. The great problem with this is that F1.7.20 and the 13th August, 1521 only work together if the TTTM correlation is out by a whole ten days, which patently it is not. Suggestions that indigenous records are in error and that 13th August, 1521 is actually F1.8.10 redress this disparity but at the cost of creating an entirely new set of inconsistencies.
In order to calculate the date of the Xiuhpohualli year-bearer one only needs to examine the Tonalpohualli count. The Julian year 1521 was contemporaneous to the year Yei Calli (Three House) in the Nahua-Mexica calendar, and the Tonalpohualli day of that designation recurs both 103 days before and 159 days after Ce Coatl in the divinatory count of that year. If F1.8.10 truly equates to the 13th of August then as Yei Calli days, either F1.3.8 (the 3rd of May) or F2.7.8 (the 18th of January) should be the year-bearer.
Indigenous accounts regarding the temporal location of the year-bearer vary as wildly as those of when the indigenous year began. In the case of the latter issue it is likely that disparate answers were given to a question that did not make a great deal of sense in terms of the Nahua-Mexica calendar, and responses may have been given in relation to the beginning of the Xiuhpohualli year, the Tonalpohualli year, the ilhuilhuiuh year, or any of the other definitions of a year by which hunters, farmers, politicians, or astronomers marked time. After all, our own seasons do not begin on January the first, and the financial year commences in April. Therefore the year-bearer date has been attributed to both the first day of the year bearing its name and to the last day. With this in mind, it is in theory only necessary to examine those days which might constitute the Yei Calli year-bearer in order to see which might be the most likely candidate. F1.3.8 (3rd of May) appears quite unsatisfactory as the beginning of any sort of year. F2.7.8 (18th of January) might be a more likely candidate being as it may be deemed to occur in the general temporal vicinity of one interpretation of the year's end, namely Izcalli (F2.7) - the first ilhuitl following the traditional six ilhuilhuiuh of frost referred to in the Florentine Codex (VII, 61):
"Cold comes once a year, in Ochpaniztli, it begins in Ochpaniztli. And for six feasts, six score days, the cold lasts. And then it ends, finishes, in Tititl. When that happened, they said: 'The frost has gone, now there will be sowing, it's sowing time, now earth will be planted, it's planting time; it's warm, mild, calm; the hour is good, right, at hand, imminent, here. They hurried and pressed on, restless, anxious, busy, worried, there was no let up; days would fly by. Anew they worked the fields..."
In these terms, Izcalli (which follows Tititl) would sound very much like a prime candidate for the beginning of a year. However, unfortunately that year would be Nahui Tochtli (Four Rabbit) - the one immediately following Yei Calli - and the year-bearer in question should in theory be one that falls at the end of a year rather than the beginning of the new one. At this juncture it therefore becomes apparent that something is very wrong with our dates and there is an impostor hiding amongst the correlation of 13th of August, Ce Coatl, and F1.8.10.
It should be recalled that F1.8.10 is derived from an attempt to adjust the indigenous records in line with those of their conquerors. It is therefore interesting to see what happens when the alteration is reversed, adjusting the Spanish account in line with the original indigenous date of F1.7.20. This operation shifts the 13th back to the 3rd of August (Julian), and although some might deem this an unacceptable distortion, it nevertheless produces a reading of the Nahua-Mexica calendar which at last makes sense. The TTTM correlation is honoured and the year-bearer suddenly falls upon F2.6.18.
Earlier on it was stated that the year-bearer date has been attributed to both the first day of the year bearing its name and to the last day. The most obvious objection to F2.6.18 as year-bearer is that the eighteenth day of an ilhuitl can hardly be considered its last day. However, it must be remembered that accounts given of when this day occurred were varied responses made across considerable barriers of both culture and language. As the last ilhuitl of the frost period, Tititl (F2.6) might be considered a worthy candidate for the end of an agricultural year, particularly as in this case it would define Izcalli (F2.7) as the first ilhuitl of the subsequent agricultural year, it being the first ilhuitl in which it was considered safe to begin planting without fear of seedlings being ruined by cold. Furthermore, if Tititl is the last ilhuitl of the year by these terms, it is therefore the eighteenth; and the eighteenth day of the eighteenth ilhuitl could certainly be considered to carry at least as much suitably symbolic resonance as, for example, the last day of the last ilhuitl (which in any case carries only series V day-signs and is therefore ineligible).
In conclusion, both indigenous testimony and simple mathematics appear to support F2.6.18 as year-bearer, thus at last establishing the Tonalpohualli count in relation to the TTTM correlation of the Xiuhpohualli calendar. This nevertheless raises serious questions regarding the dating of Cuauhtemoc's surrender to the 13th (rather than the 3rd) of August 1521, but considering the evidence against this date, it is very difficult to draw any conclusion other than that it is, for some presently unknown reason, in error.
Broader discussion of this particular problem is well beyond the scope of this narrative, and whilst it is a simple enough matter to reel off a list of ideas explaining how events of one date might have been set down as having occurred ten days later, it is not so simple to posit a suggestion which holds together under even the lightest scrutiny, let alone one which might be supported by objective evidence.
The siege of Tenochtitlan was a war of attrition which took its toll upon both sides to greater or lesser extents. Most accounts of this long drawn out battle are derived primarily from Hernan Cortés' letters to King Charles V of Spain and Bernal Díaz' History of the Conquest of New Spain. Although the former were composed more or less contemporaneous to the events described, Díaz only began writing the latter in 1568, and it was not definitively completed until 1576. Given that the 600 or so conquistadors involved in the siege would, it seems fair to assume, have been more concerned with staying alive than embarking on literary careers, and given that possibly not all of their number would have been entirely literate in the first place, the potential for European eyewitness accounts does not seem inspiring. This theoretically could limit the actual recording of the date 13th August to a small handful of individuals at best. All it might therefore take is one slip of either the hand or memory of an undoubtedly turbulent event in order to render an error which would then be repeated elsewhere and thus, by virtue of repetition, become authoritative.
On the other hand, it might be suggested that perhaps the indigenous accounts are either in error or have been deliberately tailored, and that a Mexica surrender on F1.8.10 was purposely recorded as having transpired ten days earlier. Given that the date by which the Tonalpohualli Ce Coatl aligns with F1.7.20 was apparently deemed an appropriate date for surrender in terms of its theological significance, there is a certain logic to this claim. However, it was recorded in Spanish accounts that the Mexica clearly knew that defeat was inevitable by this point, and that their continued lack of surrender seemed mystifying, particularly when one considers the terrible conditions of those still holding out in Tlatelolco. It is therefore highly unlikely that Cuauhtemoc would have bided his time in this manner, holding out for a particularly appropriate date upon which to surrender, only to attribute the act to a date occurring ten days earlier.
Alternately, 13th August is noted as being the feast day of Saint Hippolytus in the Catholic calendar. Saint Hippolytus the Martyr is historically distinguished for his near-puritanical devotion to Christian doctrine and for setting himself up in opposition to Rome in the belief that the ruling body of the church at the time was perhaps not so devout as it might be. Amongst what little is known of Saint Hippolytus is his vehement rejection of the idea of the Trinity on the grounds that only God himself can be the subject of worship. In other words, Saint Hippolytus might be seen as a fundamentalist, and as such his appeal may have been pronounced amongst the conquistadors as they fought for their lives in what must have seemed the most irredeemably heathen of alien territories. In context, if at some point a choice was made to alter the official date of the conquest, then whilst the feast day of Saint Hippolytus might only be one of a number of viable options, there is a certain symbolic symmetry in such a choice. As a rejection of pantheism, Hippolytus is as bold a statement as can be made given that he was intolerant of even the mild yet undeniably Christian pantheism of the Trinity. Attributing the victory to his feast day (whether deliberate or by error) might therefore be considered as akin to the construction of a mythic conception - the dramatic beginning of Christian (as opposed to indigenous) time in New Spain.
Whilst these ideas offered in account of a Spanish error might easily be pulled apart, they (arguably) seem the least unlikely of a number of possibilities; although for any merits they may be considered to possess, the central problem is that they are apparently beyond testing, and hence, true or not, equally beyond any serious possibility of validation. In the case of the Spanish August 13th versus the Mexican F1.7.20 it is unfortunate for our purposes that both suspects appear to possess near flawless alibis. There is no presently known answer to this problem, although that is quite different to suggesting that an answer to this problem does not exist, so for the time being the most sensible option would seem to be to focus on that which can at least be quantified - the Nahua-Mexica calendar itself.

It's work in progress, and comes at the end of a much longer essay on the nuts and bolts operation of the Tonalpohualli and Xiuhpohualli, but hopefully the relevant bits won't prove completely impenetrable. If anyone manages to read through all of it please feel free to award yourself 1 point.

[Forum Monk]

WA,
While it wouldn't surprise me to learn the Catholic Church 'fiddled' dates, 13 Aug 1521 seems locked in stone. Especially since Cortes' doings in Mexico are recorded in sequence like a diary. It would seem all of those dates would need to be adjusted.

You have a conundrum. It seems an error exists somewhere and it may have to do with when the various events were written nto the history books. Perhaps a scribe adjusted the dates at that time but there is no evidence that I can find, such a thing happened.

As I understand it, one or more of those mesoamerican calendars are aligned with solar eclipses. While the dates and visibility of eclipses are pretty accurately calculated for those fairly recent dates in the past, often the old descriptions of solar phenomenon are ambiguous and unreliable. I assume, however, that the current calendars you are working with also match the solar data.

(btw - has anyone on R.Dawkins' forum helped?)

[Digit]

I'm having trouble getting my head around the 10 day slippage. In England, if my memory serves me correctly, we waited till 11 days were needed to correct. At which time did Spain make the correction? When did the church make the correction and is what you are reading an original or a copy that was written later and the date altered to make sence to the people reading it?
Somebody writing after the change would probably have to make the correction for it to make sense to them.
Remember, Russia's October revolution is no longer celebrated in October, but in November, because of the slippage.

[War Arrow]

WA,
While it wouldn't surprise me to learn the Catholic Church 'fiddled' dates, 13 Aug 1521 seems locked in stone. Especially since Cortes' doings in Mexico are recorded in sequence like a diary. It would seem all of those dates would need to be adjusted.

You have a conundrum. It seems an error exists somewhere and it may have to do with when the various events were written nto the history books. Perhaps a scribe adjusted the dates at that time but there is no evidence that I can find, such a thing happened.

As I understand it, one or more of those mesoamerican calendars are aligned with solar eclipses. While the dates and visibility of eclipses are pretty accurately calculated for those fairly recent dates in the past, often the old descriptions of solar phenomenon are ambiguous and unreliable. I assume, however, that the current calendars you are working with also match the solar data.

(btw - has anyone on R.Dawkins' forum helped?)

Not sure about the solar eclipses but it was certainly aligned to the vernal and autumn equinox as each of these days fell roughly (within a margin of 1 day I believe) on the last day of the two main festival cycles - an alignment which also seems to keep the winter solstice at the exact middway point of the second of these two half-year cycles. Without going into great detail, it seems Mexica astronomers (and this is recent news to me) were pretty unbeatable, knew the difference between solar and sidereal time, and understood enough about the true length of the year to use an intercalary day (the nauhtetl) that seems to have been superior to the Julian system.

Dig - Spain made the correction in 1582, though it didn't happen in Mexico until 1583. By the time we got around to it we had another day (11 not 10) to compensate for. Most of the stuff I've been referring to dates from prior to 1583.

I'm starting to seriously doubt Cortez getting the date wrong. There's a lot of reasons why an innacurate indigenous date doesn't make sense, but I'm beginning to suspect they simply attributed the surrender to ten days earlier in the calendar because 20-Miccailhuitontli/1-Coatl (3rd Julian) makes more theological sense than 10-Hueymiccailhuitl/11-Cuauhtli (13th Julian) - though as they had apparently been long past the point of drinking their own piss for a good while, why not just throw in the towel on the most religiously appropriate date rather than wait an extra ten days and then record it as having happened ten days earlier?

No nothing on the Dawkins forum. Oddly enough, pretty good response on the >ahem< Doctor Who forum (that's me out of the closet then) which has a lot of articulate people, many of ecclesiastic persuasion, aside from the obvious quota of idiots of course.

My knowledge of Catholic religious history being pretty much non-existent it seemed like an idea to check out this possibility, but it looks like (barring error) the conquistadores would have no motive to record a wrong date, so I guess it's those naughty Mexicans, though to be fair, if they did deliberately backdate the day of surrender, they did it in such a way as to at least honour the integrity of their own calendar (given that it has a lot of cycles which stop working if just one date is wrongly aligned with another).

Different thing altogether, but Motecuhzoma the younger appears to have changed the year of their once every 52 years new fire ceremony - it should have happened in 1506 but was delayed until 1507 thus making the first year of that calendar round 2-Acatl rather than 1-Tochtli. So I suppose date-fudging has precedence.

[Digit]

Dig - Spain made the correction in 1582, though it didn't happen in Mexico until 1583. By the time we got around to it we had another day (11 not 10) to compensate for. Most of the stuff I've been referring to dates from prior to 1583.

I understand that WA, but my point was this, if we refer to the birth date of Alfred the Great, for example, do we use Bede's date or a date corrected for the Gregorian calender?
If the papers you are using for reference were written after Spain and Mexico made the change over, which calender date would the writer have been using?

[War Arrow]

Dig - Spain made the correction in 1582, though it didn't happen in Mexico until 1583. By the time we got around to it we had another day (11 not 10) to compensate for. Most of the stuff I've been referring to dates from prior to 1583.

I understand that WA, but my point was this, if we refer to the birth date of Alfred the Great, for example, do we use Bede's date or a date corrected for the Gregorian calender?
If the papers you are using for reference were written after Spain and Mexico made the change over, which calender date would the writer have been using?

Whoops. Sorry, Dig. That was my initial suspicion - that all Spanish sources may have been "corrected" in the sixteenth or seventeenth century, but apparently not, so it is indeed an unaltered Julian date as supported by its being mentioned specifically as August 13th the feast day of St. Hippolytus. Whilst the calendar reform entailed some adjustments (Easter I believe was one) - the Saint's days kept the same dates even though in terms of the true solar year most of them would be celebrated ten actual days earlier than they would have been for nearly a millennia.
Anyway, my copy of Cortes' letters to King Carlos V turned up in the post today and it seems that to explain the Spanish getting the date wrong would require a bigger conspiracy theory than I suspect is contained in The Da Vinci Code (not read it). I'm reluctantly forced to conclude that the indigenous date therefore refers to something that happened ten days earlier in their calendar, possibly to the day upon which they decided to surrender.

I suppose the important distinction is whether Cuauhtemoc and his pals either (a) set down a correct indigenous corellation to 13/8/21 Julian or (b) set down an incorrect corellation on the grounds of it being the most appropriately "mythic" date for surrender. If it's definitely (b) then there's no problem. If it's (a) then only time travel will settle the matter.

You know, after all this, not least all the other poorly understood aspects of the Mexican calendar that I seem to have stumbled across plausible explanations for, I'm seriously starting to wonder if I could er... dunno... deliver some sort of paper or lecture on some of this. For example, there's a section in Codex Borbonicus which lists the 52 years of a full Mexican calendar cycle and attributes a different night God as the presiding Deity of each one of these years, like so:
Ross Hassig (who is to all intents and purposes) a big knob on the subject of Mexican timekeeping cites these Gods as being generated by a part of the calendar by a process which seems horribly convoluted and is furthermore entirely reliant on the existence of one method of leap-year adjustment for which there is zero evidence in any native manuscript. Somehow I've come up with an alternative explanation for assigning a particular God to a particular year which just works once you write two sets of numbers on two pieces of paper and stick them next to each other, without need of any hypothetical and inordinately complicated extra theory to justify it.

I'm not sure I entirely subscribe to the idea of a 'club' but I've really got to wonder how I (I'm a bloody postman for crying out loud) seem to have spotted something which if obscure, is actually quite simple, that seems to make Ross Hassig (who is certainly no lightweight) look like an idiot. I hope I'm not becoming delusional. This is about the third Eureka moment I've had in the past two weeks.

[War Arrow]

Okay, for anyone who's still here... I'm bruised, my bottom hurts, and some of my clothes are still on fire, but I think I've finally nailed this puppy down to something resembling a conclusion (and one which is the opposite of my initial suspicions). This probably needs editing in order to turn it into English but here goes (and by the way the reference to the new fire ceremony refers to a ritual traditionally held in 1-Rabbit years which was moved to 2-Reed years in 1507 - with all historical records of previous ceremonies being altered in support of the new date).

The Disparity between Spanish and Mexican Records

Finally, as stated earlier, both indigenous testimony and simple mathematics appear to support F2.6.18 as year-bearer, thus at last establishing the Tonalpohualli count in relation to the TTTM correlation of the Xiuhpohualli calendar. This nevertheless raises serious questions regarding the dating of Cuauhtemoc's surrender to the 13th (rather than the 3rd) of August 1521 as corellated to Ce Coatl and F1.7.20.

Broader discussion of this particular problem is well beyond the scope of this narrative, and whilst it is a simple enough matter to reel off a list of attempted explanations for how events of one date might have been set down as having occurred ten days later, it is not so easy to posit a suggestion which is supported by objective evidence, let alone one which resists easy refutation. In his third letter to King Carlos V of Spain, Hernando Cortés wrote:

"Thus, with [Cuauhtemoc] a prisoner, it pleased God that the war should cease, and the day it ended was Tuesday, the feast of Hippolytus, the thirteenth of August in the year 1521."

The letter conveying this news is dated to 15th May 1522, and even considering the ten months that had passed at the time of writing, it is highly improbable that Cortés would have erred in regard to what was arguably the singularly most significant date of the entire conquest, particularly as the date would have remained no less significant to the great majority of his fellow conquistadors. Unfortunately, the possibility of this date being in some way deliberately falsified (August 3rd recorded as August 13th) seems equally improbable given the apparent lack of motive and the implausible complexity of any conspiracy theory by which such an adjustment (not to mention its subsequent concealment) might be explained.

Anales de Tlatelolco written in 1528 by anonymous indigenous authors state that the conquistadors offered Cuauhtemoc a chance to surrender on numerous occasions, and on the last of these the ruler apparently knew that there was a choice to be made, that the tide of the battle would not be turning in his favour. Consulting a priest on the matter of what response he might give, he was told:

"In only four days we shall have completed the period of eighty days. It may be the will of Huitzilopochtli that nothing further shall happen to us. Let us wait until these four days have passed."

This supports the suggestion that the date upon which Cuauhtemoc surrendered was in some way determined by the indigenous calendar, which in turn squares well with the general feeling amongst those attacking Tenochtitlan that Cuauhtemoc and his allies were only delaying the unavoidable. The Mexica were at this stage outnumbered on all sides and suffering rapidly deteriorating living conditions, notably being reduced to eating weeds and lizards, and drinking brackish water in the one part of the city that had not yet fallen to enemy forces. Defeat seemed inevitable, and the conquistadores knew that Cuauhtemoc must have been aware of this, despite which, the anticipated surrender never came. On August the 13th Cuauhtemoc was seen fleeing the remains of the city by canoe, and was soon apprehended, and as Anales de Tlatelolco notes:

"The city was conquered in the year 3-House [Yei Calli]. The date on which we departed [fled the city] was the day 1-Serpent [Ce Coatl] in the ninth [trecena]."

This is notable in so much as Ce Coatl is (in terms of its auguries) held to be a propitious day for trade and commerce which, given the social and economic structure of Mesoamerican society as a whole, equates to a propitious day upon which to begin a journey.

Folio 87v of Codex Rios aligns the events described above to the mummy bundle pictogram of Miccailhuitontli (F1.7) - depicting the full twenty day period (therefore demarcating its last day as that upon which Cuauhtemoc surrendered) as the culmination of a one-hundred day siege described by the pictograms for Miccailhuitontli and the four preceding ilhuilhuiuh. This might at least suggest that the brief conversation related in Anales de Tlatelolco took place on F1.7.16, four days before the end of Miccailhuitl. As an aside, at this juncture it should perhaps be noted that although the dates remain consistent, accounts vary greatly on the duration of the siege.

As has been noted, whilst the dates F1.7.20 and Ce Coatl are consistent with the TTTM corellation, the alignment of these dates to 13th August 1521 is not. Given that there is little reason to doubt the veracity of the Spanish account in this instance, there appears to be only one possibility. Given the significance of certain dates in the indigenous calendar, one is reluctantly forced to conclude that F1.7.20 and Ce Coatl were recorded as suitably mythic terminators to the close of one phase of history just as Ce Tochtli fire ceremonies were retroactively recorded as having occured in Ome Acatl years. Possibly the indigenous date acquired mythic significance during the preceding days, but once it had passed it became evident that Huitzilopochtli was not be about to intervene after all, contrary to hopes related in Anales de Tlatelolco.

Certainly the end of Tenochtitlan occurred in such a shambolic manner as to preclude much possibility of any deliberately chosen date. Whilst Cuauhtemoc's surrender has been mentioned many times thus far, it should be remembered that the Mexica never offered any formal surrender. On 13th August 1521, Cuauhtemoc was captured as he fled the city. Upon being brought before Cortés he initially asked to be put to death, and only when this request was denied was anything approaching a surrender offered. Inevitably, with their leader held prisoner, what few Mexica were still waiting out the seige realised that the conquest was over. Perhaps then F1.7.20 and Ce Coatl refer to the point at which those concerned realised it really was over, after which their continued resistance was maintained only in lieu of any better ideas of how to proceed.

[Ishtar]

Anyone here know of any incident in which the Catholic church is known to have fiddled the books and made a slight adjustment to a particular recorded date for whatever reason?

Tons!

The Catholics as Romans were masters at taking the local pagan festivals of wherever they conquered, and transplanting Christian festivals on top of them and then, because they didn't understand the signficance of astrological timings, moving the date to suit their own, usually political, agendas.

E.g. December 25 being the birth of Christ. They pinched it from Mithras, or what was more commonly known in pagan circles worldwide at the time as the Day of the Birth of the Sun God (not the Day of the Birth of the Son of God).

Also another pagan festival, Easter - where the Catholics changed its function and its date:

Easter is named after a pagan goddess (Eostre) and was always celebrated on the Spring equinox (usually 21 March). The Christians took it for the crucifixion and then at the council of Nicea in 325 AD, decided it should always fall on the first Sunday 14 days after the full moon. That's why it's always on a different date every year.

[Digit]

Easter was fiddled as well so as not to clash with the 'pagan' Jewish festival of Passach, Passover to you not of the true faith.
Sorry Min!
I'm not sure if my understanding is the same as yours Ish but I've always understood Easter to fall on the first Sunday after the full Moon after the spring equinox.
The early Christians of course celebrated Passover, Do this in memory of me!

[Ishtar]

Hi Dig - you of the true faith! How are you today?

I knew the RC Church changed it at Nicea, but I wasn't sure about how Easter is now worked out so I had a look on Wikipedia. I've just had another look and you're right. I was getting it mixed up with the Jewish Paschal Moon.

Actually, if you fancy a good laugh you might want to read about all the Christian ummings and errings about the date of Easter on Wikipedia: http://en.wikipedia.org/wiki/Easter