Blinking snake

Mayan Time Periods and Period Glyphs

Constellation band

The table below shows various periods, from one day up to the largest known, and period glyphs for some of them. Some periods do not have glyphs, because we’ve never seen them; the largest known date on the monuments is

at Cobafootnote, and the Mayans only carved the numbers, not the associated period glyphs.

The table goes up to the largest cycle shown at Coba, but since we don’t have a clue what the names of any of these huge periods were, I’ve simply lettered them. The largest one, then, is the “N” cycle. Just to give some idea how large a number this is, the Earth weighs approximately 66 sextillion tons, which fits between the “H” and the “I” cycles. There are probably more days in the Coba date than atoms in the universe. .footnote

K’in (Kin)
1 Day
Kin Kin Kin Kin Kin Kin Kin Kin Kin Kin Kin Kin Kin Kin Kin Kin Kin Kin Kin Kin Full-figure kin
Winal (Uinal)
20 Days
Winal Winal Winal Winal Winal Winal Winal Winal Winal Winal Winal Winal Winal Winal Winal Winal Winal Full-figure winal
360 Days
The “computing year”
Tun Tun Tun Tun Tun Tun Tun Tun Tun Tun Tun Tun Tun Tun Tun Tun Tun Tun Tun Full-figure tun
K’atun (Katun)
7,200 Days
20 computing years
201 Tuns
Katun Katun Katun Katun Katun Katun Katun Katun Katun Katun Katun Katun Katun Katun Katun Katun Full-figure katun
Bak’tun (Baktun)
144,000 Days
400 computing years
202 Tuns
Baktun Baktun Baktun Baktun Baktun Baktun Baktun Baktun Baktun Baktun Baktun Baktun Full-figure baktun
Piktun (Pictun)
2,880,000 Days
8,000 computing years
203 Tuns
Piktun Piktun Piktun Piktun Piktun Piktun Piktun Piktun Piktun Piktun Piktun Piktun
Kalabtun (Calabtun)
57,600,000 Days
160,000 computing years
204 Tuns
Kalabtun Kalabtun Kalabtun Kalabtun Kalabtun Kalabtun Kalabtun Kalabtun Kalabtun Kalabtun Kalabtun Kalabtun
K’inchiltun (Kinchiltun)
1,152,000,000 Days
3,200,000 computing years
205 Tuns
Kinchiltun Kinchiltun Kinchiltun Kinchiltun Kinchiltun Kinchiltun Kinchiltun Kinchiltun
Alawtun (Alautun)
23,040,000,000 Days
64,000,000 computing years
206 Tuns
Alawtun Alawtun Alawtun Alawtun Alawtun Alawtun
Alawtun Alawtun Alawtun Alawtun Alawtun Alawtun
“Hablatun” footnote
460,800,000,000 Days
1,280,000,000 computing years
207 Tuns
Hablatun Hablatun Hablatun Hablatun 460 billion 800 million Days; 1 billion 280 million Tuns
9,216,000,000,000 Days
25,600,000,000 computing years
208 Tuns
“A” tun “A” tun “A” tun “A” tun 9 trillion 216 billion Days; 25 billion 600 million Tuns
184,320,000,000,000 Days
512,000,000,000 computing years
209 Tuns
“B” tun “B” tun “B” tun “B” tun 184 trillion 320 billion Days; 512 billion Tuns
3,686,400,000,000,000 Days
10,240,000,000,000 computing years
2010 Tuns
“C” tun “C” tun “C” tun “C” tun 3 quadrillion 686 trillion 400 billion Days; 10 trillion 240 billion Tuns
73,728,000,000,000,000 Days
204,800,000,000,000 computing years
2011 Tuns
73 quadrillion 728 trillion Days;
284 trillion 800 billion Tuns
1,474,560,000,000,000,000 Days
4,096,000,000,000,000 computing years
2012 Tuns
1 quintillion 474 quadrillion 560 trillion Days;
4 quadrillion 96 trillion Tuns
29,491,200,000,000,000,000 Days
81,920,000,000,000,000 computing years
2013 Tuns
29 quintillion 491 quadrillion 200 trillion Days;
81 quadrillion 920 trillion Tuns
589,824,000,000,000,000,000 Days
1,638,400,000,000,000,000 computing years
2014 Tuns
589 quintillion 824 quadrillion Days;
1 quintillion 638 quadrillion 400 trillion Tuns
11,796,480,000,000,000,000,000 Days
32,768,000,000,000,000,000 computing years
2015 Tuns
11 sextillion 796 quintillion 480 quadrillion Days;
32 quintillion 768 quadrillion Tuns
235,929,600,000,000,000,000,000 Days
655,360,000,000,000,000,000 computing years
2016 Tuns
235 sextillion 929 quintillion 600 quadrillion Days;
655 quintillion 360 quadrillion Tuns
4,718,592,000,000,000,000,000,000 Days
13,107,200,000,000,000,000,000 computing years
2017 Tuns
4 septillion 718 sextillion 592 quintillion Days;
13 sextillion 107 quintillion 200 quadrillion Tuns
94,371,840,000,000,000,000,000,000 Days
262,144,000,000,000,000,000,000 computing years
2018 Tuns
94 septillion 371 sextillion 840 quintillion Days;
262 sextillion 144 quintillion Tuns
1,887,436,800,000,000,000,000,000,000 Days
5,242,880,000,000,000,000,000,000 computing years
2019 Tuns
1 octillion 887 septillion 436 sextillion 800 quintillion Days;
5 septillion 242 sextillion 880 quintillion Tuns
37,748,736,000,000,000,000,000,000,000 Days
104,857,600,000,000,000,000,000,000 computing years
2020 Tuns
37 octillion 748 septillion 736 sextillion Days;
104 septillion 857 sextillion 600 quintillion Tuns
754,974,720,000,000,000,000,000,000,000 Days
2,097,152,000,000,000,000,000,000,000 computing years
2021 Tuns
754 octillion 974 septillion 720 sextillion Days;
2 octillion 97 septillion 152 sextillion Tuns
The Coba Number
10,331,233,010,526,315,789,473,682,240,000 Days
28,697,869,473,684,210,526,315,784,000 computing years
10 nonillion, 331 octillion, 233 septillion, 10 sextillion, 526 quintillion, 315 quadrillion, 789 trillion, 473 billion, 682 million, 240 thousand Days

28 octillion, 697 septillion, 869 sextillion, 473 quintillion, 684 quadrillion, 210 trillion, 526 billion, 315 million, 784 thousand Tuns


footnote Coba is a ruin in northeastern Yucatan, near Tulum, sixty miles or so from Chichén Itza; during Classic times, it was the largest city in the area (Hunter, 1986).

footnote Well, not really. I did some checking on the number of atoms in the universe. Here’s what I found:

Message-Id:  <Pine.ULT.3.91.960404110732.18731V-100000 at>
Date:         Thu, 4 Apr 1996 12:18:03 -0500
From: Iosif Vaisman <>
Subject:      Re: Help-# atoms universe
To: Multiple recipients of list CHMINF-L

On Wed, 3 Apr 1996, R. Scott Jokerst wrote:
> The calculation is not possible.  Any credible astronomer will tell you
> they have no idea what the mass of the universe is, at any level of
> approximation.  It’s size is also undetermined, and keeps getting “bigger”

Not exactly. Some quite credible astronomers have some ideas. E.g.:

|       AUTHOR:  Jungman, G.; Kamionkowski, M.; Kosowsky, A.; Spergel, D.N.
|        TITLE:  Weighing the Universe with the cosmic microwave background
|       SOURCE:  Physical Review Letters, vol.76, no.7, p. 1007-10 (1996)

|       AUTHOR:  Carvalho, J.C.
|        TITLE:  Derivation of the mass of the observable Universe
|       SOURCE:  International Journal of Theoretical Physics, vol.34, no.12,
|                p. 2507-9 (1995)

|       AUTHOR:  Tardif, J.
|        TITLE:  A method for the estimation of the mass of the universe
|       SOURCE:  Speculations in Science and Technology, vol.17, no.2,
|                p. 135-136 (1994)

|       AUTHOR:  Loh, E.D.; Spillar, E.J.
|        TITLE:  A measurement of the mass density of the Universe
|       SOURCE:  Astrophysical Journal. Letters to the Editor, vol.307, no.1,
|                pt.2, p. L1-4 (1986)

|       AUTHOR:  Peebles, P.J.E.
|        TITLE:  The mean mass density of the Universe
|       SOURCE:  Nature, vol.321, no.6065, p. 27-32 (1986)

|       AUTHOR:  Peebles, P.J.E.
|        TITLE:  The mass of the Universe
|       SOURCE:  Ann. New York Acad. Sci. (USA), Annals of the New York
|                Academy of Sciences, vol.375, p. 157-68 (1981)

As to the number of atoms in the Universe Neil de Grasse Tyson in his
“Universe down to Earth” (Columbia University Press, 1994) writes about
10^81. Other recent estimates range between 10^70 and 10^90. Of course,
few atoms here and there may be not accounted for.

Iosif Vaisman

So then I did some calculations, using Python, a full-featured programming language available for Unices, Linux, Mac and Windows OSs. ** is used for exponentiation, and _ means to substitute the previous answer in the formula.

Here are my results:

Python 2.4 (#60, Nov 30 2004, 11:49:19) [MSC v.1310 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> 20**21
>>> _*360
>>> 10**70
>>> 10**81
>>> 10**90

So I was a little off ;-).

snail crawling

footnote The “Hablatun” name has only been reported by Spinden, so it is very unlikely to actually have been in use. In fact, all terms for periods larger than k’atun should be viewed with a skeptical eye. K’atun and smaller periods shown in the table are attested to and used by Mayans, but bak’tun seems to be an invention of Mayanists rather than Mayans. Recent advances in translation have shown that the glyph for the 144000-day period should most probably be translated as pi or pih, a term meaning “bundle.” None of the terms for periods greater than 144000 days are attested. They should be recognized for what they are: terms invented for the convenience of Western anthropologists, archaeologists and epigraphers. See any of the recent Notebooks by Linda Schele (et al.) for a detailed discussion.


Gates, William E., An Outline Dictionary of Maya Glyphs, Johns Hopkins Press, 1931.
Hunter, C. Bruce. A Guide to Ancient Maya Ruins: Second Edition, Revised and Enlarged. Norman: University of Oklahoma, 1986 (first edition 1974).
Schele, Linda and Nikolai Grube, Notebook for the XXIst Maya Hieroglyphic Workshop, “The Dresden Codex,” Department of Art and Art History, The College of Fine Arts, and The Institute of Latin American Studies, University of Texas, Austin, 1997.
Schele, Linda, Nikolai Grube and Simon Martin, Notebook for the XXIInd Maya Hieroglyphic Forum, “Deciphering Maya Politics,” Department of Art and Art History, The College of Fine Arts, and The Institute of Latin American Studies, University of Texas, Austin, 1998.
Schele, Linda and Peter Matthews, “Numbers,” Unpublished Chapter III of Maya Writing Book, Maya File 212, n.d.
Spinden, Herbert J., “The Reduction of Maya Dates,” in Papers of the Peabody Museum of American Archaeology and Ethnology, Harvard University, Vol. VI, no. 4, Peabody Museum, 1924, pp. 1-286.
Spinden, Herbert J., A Study of Maya Art: Its Subject Matter & Historical Development, Dover, New York, 1975. (Original publication 1913; With a New Introduction & Bibliography by J. Eric S. Thompson.)

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