Was the Beginning Day of the Maya Month Numbered Zero (or Twenty) or One?

In Short

This technical inquiry examines a specific mechanism within the Maya calendar system: whether the first day of a month was labeled as one, zero, or twenty. By analyzing data from the Dresden Codex and stone inscriptions at sites like Palenque and Copan, the text tests the hypothesis that the Maya counted elapsed time rather than current days. It is a work of philological and mathematical detective work, serving as a primary document for those interested in the rigorous methods used by early twentieth-century scholars to decode Mesoamerican chronology.

The Story

The narrative begins with a challenge to the established understanding of Maya notation. A scholar named Goodman proposed that the Maya calendar functioned similarly to how modern people count minutes or hours: by recording the amount of time that has already passed, rather than the day one is currently experiencing. If this theory holds, the Maya month did not begin with Day 1, but rather with a day represented by a special glyph that indicates the completion of the previous cycle. To test this, the investigation turns to the Dresden Codex, a crucial manuscript containing rows of month dates.

The author systematically works through the arithmetic of these dates. By taking a recorded date and adding the number of days specified in the codex, he calculates the destination date. If the standard assumption (beginning with 1) were correct, the calculations would land on specific days; however, in several instances, the actual glyphs carved or painted in the documents point to a different conclusion. When the math is performed using the "zero" or "twenty" hypothesis, the results align with the historical evidence provided in the manuscripts. For example, adding ninety days to a specific date in the codex points not to a day within the expected month, but to the start of the following month, marked by the mysterious glyph in question.

The inquiry then shifts from the portable codex to the monumental stone inscriptions of the Maya world. At the Temple of the Cross at Palenque, the author identifies a sequence of dates that reinforces the findings from the manuscripts. By calculating the distance between these monumental dates, he shows that the "zero" or "twenty" sign appears consistently where a beginning day is expected. He acknowledges that errors exist—some glyphs are worn or appear to be carved incorrectly—but he argues that these anomalies are likely mistakes by ancient stonecutters rather than evidence against the system itself.

The final act of the argument addresses the philosophical and linguistic question: was this sign actually a "zero" or a "twenty"? While the author admits that it is functionally irrelevant for the sake of calculation—the sign behaves as a zero in every mathematical operation—he leans toward the interpretation that it represented "zero." He posits that the Maya likely viewed the first day as having zero elapsed days of the current month. He concludes that while one cannot be entirely certain of the mental framework of an ancient civilization, the most coherent and mathematically sound explanation is that the Maya numbered their month days from zero to nineteen.

How It Unfolds

The premise of the count The author introduces the central tension: the difference between counting a current day versus counting elapsed time. He lays out Goodman’s theory that the Maya used a system of elapsed time, which would place the start of the month at a value of zero or twenty.

The evidence of the codex The focus shifts to the Dresden Codex, where the author tests the theory against specific mathematical sequences. By performing the arithmetic on these dates, he demonstrates that the data points consistently to a month-start value that is not one.

The validation of stone inscriptions The investigation moves to physical ruins at sites like Palenque and Tikal. The author cross-references the calculations with the stone carvings, showing that the same "zero or twenty" glyphs appear in the monuments exactly where the math predicts they should.

The conclusion of intent The author closes by synthesizing the evidence and addressing the final ambiguity of the glyph's meaning. He arrives at the conclusion that the system is best understood as a zero-to-nineteen count, as this is the most reliable way to maintain the integrity of their calendar calculations.

The People

The text is driven by the ideas of two primary figures: Charles P. Bowditch, the author, and Goodman, the theorist.

Goodman acts as the provocateur. His work on Maya inscriptions provides the framework for the entire study; he is the one who dares to suggest that the Maya calendar follows an "elapsed time" logic rather than the intuitive "current day" logic. His reliance on tables and his systematic approach invite both scrutiny and support. He serves as the intellectual catalyst, providing the hypothesis that keeps the investigation moving.

Bowditch acts as the judge and the navigator. He is precise, cautious, and methodical. He does not take Goodman’s theory for granted; instead, he subjects it to a series of tests using the Dresden Codex and stone inscriptions. Bowditch is wary of over-interpreting the ancient mind, often reminding the reader that we cannot know for certain what a culture "intended" to mean by a specific symbol. He is motivated by the desire for mathematical accuracy and the reduction of error. By the end, he is transformed from a skeptic of the theory into an advocate for it, having found that the "zero" hypothesis is the only one that resolves the irregularities found in the ancient texts.

In Its Own Voice

Goodman, in his elaborate and valuable book on the Maya Inscriptions, has made up his Tables on the supposition that the beginning day of the month was not called Day 1, but Day 20, giving the day this number because in his view the Mayas counted the number of days which had passed and not the current or passing day.

The author identifies the foundational theory of the book, contrasting the "elapsed time" method against the conventional way we count days today.

On the whole, therefore, I think the weight of evidence is in favor of the hypothesis that the Mayas called the beginning days of their month Day 0 and numbered the days of their month from 0 to 19.

This statement serves as the final verdict of the author, summarizing his interpretation of the archaeological and mathematical evidence.

What It's Really About

The book is an inquiry into the nature of mathematical logic in non-Western systems. At its core, it asks how a civilization records time when its numerical base does not align with the linear, ordinal counting we use in the modern West. The argument is that the Maya calendar was not merely a way to track sun cycles, but a rigorous, zero-based mathematical system that prioritized the completion of units. The book explores the tension between human intuition—which wants to start counting at one—and the structural necessity of a placeholder that acknowledges that "nothing" of the current month has yet occurred. It is a study of how ancient systems of thought prioritize calculation over standard naming conventions.

Why Read It Today

Readers who enjoy the history of mathematics, archaeology, or the rigorous, step-by-step resolution of historical puzzles will find this work rewarding. It offers a rare, unobstructed view into the process of scientific discovery in the early 1900s, where the tools were paper, ink, and raw data from the field. It is not a light read; it requires the reader to follow the author through complex, multi-step calculations and to keep track of various Maya month names and glyph functions.

The prose is dry, academic, and entirely lacking in the embellishment common in modern popular history. It feels like looking over the shoulder of a scholar at his desk in 1901, where the value lies in the clarity of the logic rather than the narrative flair. You will walk away with a profound respect for the complexity of Maya timekeeping and a realization of how difficult it is to strip away our own cultural biases when interpreting the logic of an ancient, vanished society. If you have the patience to parse the calculations, the book provides a masterclass in how to build a case from fragmentary evidence, proving that even a single, well-placed glyph can change our understanding of a whole civilization.