The Haab’ — Solar 365-Day Calendar of the Maya

The Haab’ is the 365-day solar calendar of the Maya, a “vague year” of 18 named months of 20 days each followed by a 5-day period called Uayeb. Together with the 260-day Tzolkin sacred almanac and the Long Count, the Haab’ forms one of the three principal counts of the Maya calendar system. Where the Tzolkin answered “what kind of day is it?” and the Long Count answered “how many days have passed since the creation?”, the Haab’ answered “what time of year is it?” — anchoring the ritual and agricultural life of the community to the solar year and the seasons of planting, growing, and harvest.

The Haab’ is called haab’ in Yukatek Maya, huy haab’ in some highland K’iche’an languages, and hab’ in the Cholan languages. The word is cognate with hab’ “rain, year” in many Mayan languages, and the cycle is sometimes called the “rain year” or “solar year” in modern discussions. The 365-day Haab’ is not corrected by leap days and so drifts against the tropical year by roughly one day every four years; the 52-year Calendar Round is the smallest cycle after which the combined Haab’-Tzolkin position recurs exactly.

The structure of the year

The Haab’ year is built from 19 named periods:

• 18 months (uinal, pl. uinalob’) of 20 days each
• 1 month of 5 days at the end, the Uayeb

The 18 × 20 = 360 days plus the 5 Uayeb = 365 days. The Haab’ thus gives a year of 18 “twenties” plus the closing Uayeb, a structure that mirrors the vigesimal basis of the Maya number system.

The 18 uinalob’ are not numbered; instead, each has its own name and its own presiding spirit. The 19th period, the Uayeb, is the dangerous time outside the year, when the days are not part of the 18 named months and when the year-boundaries are sealed.

The 18 months and the 5-day Uayeb

In their canonical order, beginning with the first day of the Haab’ year, the 18 months and the closing Uayeb are:

The order is fixed and attested from the Late Preclassic through the Late Classic and into the colonial era. Modern K’iche’, Kaqchikel, and Tz’utujil daykeepers in highland Guatemala preserve the same sequence under K’iche’an orthography, and the Yukatek Chilam Balam books preserve the names in colonial spelling.

The day-count within the Haab’

Each 20-day month is numbered 0 through 19. The day-count begins with 0 Pop (literally “seating of the mat,” the installation of the year’s first month), advances to 19 Pop (the last day of the first month), then to 0 Wo (the seating of the frog), and so on. The “0 day” is the seating day, the inaugural day of the month, and the “19 day” is the closing day. The system of 0–19 within each month is an instance of the Maya zero and place-value arithmetic, and the 0-day of each month is written with a shell or face glyph in the inscriptions.

The closing 5-day period, Uayeb, is not numbered with the 0–19 scheme; its days are simply 1 Uayeb through 5 Uayeb (or, in some colonial sources, “0 Uayeb” through “4 Uayeb”). The 5 days of Uayeb are dangerous, and no important event is scheduled to begin during them.

The role of the Uayeb

The Uayeb is the closing 5 days of the Haab’ year, the time outside the 18 named months, when the year-boundary is sealed. The 5 days were a time of fasting, abstinence, and ritual waiting. No marriages were scheduled, no business was transacted, and no long journeys were undertaken. The daykeeper and the elder men and women of the community observed the Uayeb with ritual abstention, and the period is associated in colonial sources with the time when the gods were deciding the fate of the coming year.

Modern highland daykeepers continue to mark the Uayeb, although the period is now more syncretically tied to the Christian calendar (the Uayeb often falls near All Saints’ Day in the highland K’iche’ ritual year). The 5-day period is sometimes extended in modern practice to include 6 or 7 days, with the daykeeper reserving the closing day for a final reading.

The Haab’ and the agricultural year

The 18 months are tied to the agricultural year in the Maya lowlands, with each month corresponding to a phase of maize cultivation and to a season of the climatic cycle. The correspondence is approximate, and the months shift against the seasons by roughly 1 day every 4 years (the Haab’ has no leap-day correction); the tropical year is actually 365.2422 days, so the 365-day Haab’ is short by about a quarter-day per year.

• Pop, Wo, Sip, Sotz’ (months 1–4): late winter, the time of first plowing and the burning of milpa fields.
• Sek, Xul (months 5–6): the dry-rain transition, the time of maize planting.
• Yaxkin, Mol, Ch’en (months 7–9): the early rains, the time of maize seedling growth.
• Yax, Sak, Kej (months 10–12): the mid-rains, the time of maize-tasseling and bean harvest.
• Mak, K’ank’in, Muwan (months 13–15): the late rains, the time of maize-grain fill.
• Pax, K’ayab, Kumk’u (months 16–18): the dry-season harvest, the time of maize storage.
• Uayeb: the dangerous time, the year-boundary fast.

The correspondence is loose; the actual tropical year shifts by 1 day every 4 Haab’ years, so the months slip against the actual seasons by about 13 days per century. A child born in 0 Pop of one 52-year Calendar Round might find, 52 years later, that 0 Pop falls not at the time of plowing but at the time of maize-tasseling.

The Haab’ in the inscriptions

The Haab’ is recorded in the inscriptions alongside the Tzolkin position. A typical Classic-period date reads:

9 Ik’ 5 K’an — 14 Mak

The first clause, 9 Ik’ 5 K’an, is the Tzolkin position: 9 Ik’ as the primary date, with 5 K’an as the secondary (or “half-Tzolkin” position 9 days later). The second clause, 14 Mak, is the Haab’ position: the 14th day of the month Mak. Together, the two clauses specify a single day in the 18,980-day Calendar Round.

The Haab’ position is written with a day coefficient (0–19) and a month glyph, and the full set of 19 month glyphs is among the most commonly attested in the Maya writing system. The month glyphs are attested from the Late Preclassic (Tres Zapotes Stela C carries a Haab’ month) through the Late Classic and into the colonial codices.

The role of 0 Pop and the New Year

The 0 Pop day — the first day of the Haab’ year, the seating of the mat — was a major ritual occasion. The 0 Pop day, like the modern Mayan New Year celebrated in the highland communities, marked the renewal of the year, the bringing-in of the new fire, and the beginning of the agricultural cycle. In the colonial-era K’iche’ communities of highland Guatemala, the 0 Pop day was marked with a community-wide ceremony, the consultation of the daykeeper, the erection of new shrines, and the burning of effigies of the old year.

The 0 Pop day was, in the Classic period, a time of royal ritual. Tikal and Copán inscriptions record the 0 Pop day as a time of accession, sacrifice, and the dedication of monuments. The Haab’-year renewal was a moment of cosmic rebalancing, and the king used the occasion to demonstrate his role as the intermediary between the human and the divine.

The Haab’ and the 365-day year in Mesoamerica

The 365-day vague year is universal in Mesoamerica, attested in the Zapotec, Mixtec, Aztec, and Maya cultures, and the 18-month + 5-day structure is shared with the Aztec xiuhpohualli. The two calendars are very similar in structure, with the principal difference being the names of the months: the Aztec xiuhpohualli begins with Atemoztli and ends with Izcalli, while the Maya Haab’ begins with Pop and ends with Uayeb. The correspondence of the 19-month structure suggests a common origin in the Middle to Late Preclassic, with the divergence in month-names reflecting local ritual traditions.

The Haab’ and the 52-year cycle

The combined Calendar Round of Haab’ + Tzolkin has a least common multiple of 18,980 days = 73 Tzolkin cycles = 52 Haab’ years. This 52-year cycle is the smallest time after which a given combined Calendar Round position (i.e., a particular Haab’ day and Tzolkin day together) recurs. The 18,980-day cycle is the basis of the Mesoamerican New Fire ceremony, with the highland communities observing the 52-year cycle as a time of renewal and fear.

The 18,980-day cycle is not a named “century” in the European sense; the Maya did not speak of a “century” in the way the Western tradition does. Yet a 52-year period is documented ethnohistorically as a time of ritual renewal, and the closing days of such a cycle were feared as a moment of cosmic vulnerability. The Spanish chronicler Bernardino de Sahagún recorded the Aztec version of this anxiety in his Florentine Codex; the parallel Maya traditions are preserved in the Chilam Balam books and in colonial-era K’iche’ ritual texts.

The Haab’ and the k’atun

The Haab’ position is sometimes used in inscriptions as a way of specifying a k’atun ending. The 9.0.0.0.0 Long Count, for example, fell on 13.0.0.0.0 + 9 baktuns = 1,296,000 days after the base date, which corresponds (in the GMT correlation) to AD 435 and to a particular Haab’ position. The 10.0.0.0.0 Long Count fell on AD 830, and the 11.0.0.0.0 Long Count on AD 1224. The Haab’ position of these baktun endings is recorded in the inscriptions of the Late Classic and is used by epigraphers to verify the absolute date.

The 360-day tun and the 365-day Haab’

The 18 × 20 = 360-day tun is the Long Count’s “year” — the basis of the tun and katun periods of the Long Count. The 360-day tun is shorter than the 365-day Haab’ by 5 days, and the 365-day Haab’ is shorter than the 365.2422-day tropical year by about 11 minutes per day or 5 days every 100 years. The 360-day tun is a useful approximation for the Long Count, but the 365-day Haab’ is the actual solar year of ritual life.

The 5-day Uayeb corresponds to the gap between the 360-day tun and the 365-day Haab’; in a sense, the Uayeb is the “tropical correction” of the 360-day tun, an acknowledgement that the 5 days between the 18 named months and the year-boundary are outside the 18-month structure.

The Haab’ in the codices

The almanacs of the Dresden Codex, the Madrid Codex, and the Paris Codex are all keyed to the Haab’ as well as the Tzolkin. The eclipse tables in the Dresden Codex, the Venus tables, and the Mars tables all carry Haab’ month glyphs as column or row headers, and the daykeeper reading the table would cross-reference the Haab’ position with the Tzolkin position to determine the exact day. The Haab’ is the calendar of agricultural time, and the codices are built on agricultural time as the framework for the almanacs.

The Haab’ in the modern highland calendar

The 365-day Haab’ is rarely used in modern K’iche’ and Kaqchikel ritual practice; the dominant modern cycle is the 260-day Tzolkin, with the daykeeper selecting the day for ceremonies and naming. The 18-month structure survives in some agricultural rituals — particularly the ceremonies tied to the first maize harvest (Sak and Kej months) — and the 0 Pop day is still marked in the highland communities. The 5-day Uayeb has been largely absorbed into the Christian liturgical year, with the highland communities marking the 5 days with fasting and abstention as in the pre-conquest calendar.

The Haab’ and the 819-day cycle

The 819-day cycle of Caracol does not map neatly onto the Haab’; 819 days is just over 2 Haab’ years and 89 days, and the cycle does not return to the same Haab’ position. The 819-day cycle is tied instead to the Tzolkin, the 9-day Lords of the Night, the 13-day trecena, and the 4-color cardinal cycle. The Haab’ and the 819-day cycle are structurally independent, although both rotate within the 18,980-day Calendar Round.

The Haab’ as a cultural system

The Haab’ is more than a year; it is a cultural framework that links the solar year, the agricultural cycle, the milpa planting and harvest, the Maya cuisine and feasting, and the ritual bloodletting and sacrifice that marked the agricultural year. To live in the Haab’ is to live in the rhythm of the maize plant: the planting at Sek, the first green at Yax, the harvest at Sak, the storage at Kumk’u. The cycle of 18 months is the cycle of maize, the staple crop that the Maya considered the substance of human life.

Related pages

• The Maya Calendar System
• The Tzolk’in: Sacred 260-Day Calendar
• The Long Count and Calendar Round
• Maya Astronomical Cycles and Observations
• How does the Maya Long Count calendar work?
• What is a katun in Maya timekeeping?
• Maya Writing, Language, and Books
• Maya Agriculture, Food, and Cuisine

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