About the Mayan Calendar Converter
This Mayan calendar converter shows how any day is written in the three interlocking calendars of the ancient Maya: the Long Count (bak’tun.k’atun.tun.winal.k’in), the 260-day Tzolk’in sacred calendar and the 365-day Haab’ solar calendar. It also gives the Lord of the Night (G1–G9) and the total day count since the Maya creation date. You can also enter a Long Count read from a monument and get the matching Gregorian and Julian calendar dates.
It is useful for students and travellers decoding stelae at Tikal, Copán or Palenque, for teachers building a lesson on Maya mathematics, and for anyone curious about their birthday as a Tzolk’in day sign — the basis of the day-keeping still practised in the Guatemalan highlands.
Linking Maya dates to ours needs a correlation constant. The default is the widely accepted Goodman–Martínez–Thompson (GMT) value of 584,283, under which the creation date 13.0.0.0.0 4 Ajaw 8 Kumk’u is 11 August 3114 BCE in the proleptic Gregorian calendar (6 September 3114 BCE in the Julian calendar) and the famous 13.0.0.0.0 4 Ajaw 3 K’ank’in fell on 21 December 2012. The alternative 584,285 shifts every result by two days.
How to use the mayan calendar converter
- 1Choose whether to convert a modern date or a Long Count.
- 2Enter the Gregorian date, or the five Long Count numbers from bak’tun to k’in.
- 3Keep the GMT correlation unless you specifically follow the 584,285 variant.
- 4Read the Long Count, Tzolk’in day sign, Haab’ date and Lord of the Night.
- 5For ancient dates, use the Julian calendar date that historians normally quote.
Formula and method
The Long Count is a place-value count of days since the Maya creation date: 1 k’in = 1 day, 1 winal = 20 k’in, 1 tun = 18 winal (360 days), 1 k’atun = 20 tun (7,200 days) and 1 bak’tun = 20 k’atun (144,000 days). The converter turns the date into a Julian Day Number, subtracts the correlation constant to get the day count n, and divides n into those units.
The Tzolk’in pairs a number 1–13 with one of 20 day signs, and the Haab’ has 18 named months of 20 days plus the 5-day Wayeb’. Both cycles are aligned so that day 0 is 4 Ajaw 8 Kumk’u, which gives the offsets in the formula. The Lords of the Night are a 9-day cycle with day 0 equal to G9.
- n
- Days elapsed since 13.0.0.0.0 (creation)
- JDN
- Julian Day Number of the date
- 584,283
- GMT correlation constant (JDN of the creation date)
Worked examples
September 29, 2026 in the Maya calendars
September 29, 2026 is 1,877,030 days after the creation date under the GMT correlation. Dividing gives 13 bak’tun, 0 k’atun, 13 tun, 17 winal and 10 k’in, so the Long Count is 13.0.13.17.10. The calendar round is 3 Ok 3 Yax.
The end of the 13th bak’tun
13.0.0.0.0 is 13 × 144,000 = 1,872,000 days after creation. With the GMT constant that is Friday, December 21, 2012 — the much-publicised “end of the Maya calendar,” which was really the start of a new bak’tun on 4 Ajaw 3 K’ank’in.
New Year’s Day 2000 with the 584,285 correlation
Under the standard GMT constant January 1, 2000 is 12.19.6.15.2 11 Ik’ 10 K’ank’in. Switching to 584,285 removes two days from the count, giving 12.19.6.15.0 9 Ajaw 8 K’ank’in.
Frequently asked questions
What is my Mayan birthday sign?+
Your Tzolk’in day — a number from 1 to 13 and one of 20 day signs such as Ajaw, Imix or K’an — is what people usually mean by a Mayan birthday or nawal. Enter your birth date to see it; it comes round again every 260 days.
Did the Maya calendar end in 2012?+
No. December 21, 2012 (13.0.0.0.0) simply completed the 13th bak’tun of the current era, much like an odometer rolling over. Maya inscriptions refer to dates far beyond 2012, and the count continues with 13.0.0.0.1 and onward.
What is the GMT correlation?+
The Goodman–Martínez–Thompson correlation sets the Maya creation date to Julian Day Number 584,283, linking Long Count dates to the European calendar. It is supported by colonial-era records and radiocarbon dating and is used by most Mayanists; some prefer 584,285.
What are the Tzolk’in and Haab’?+
The Tzolk’in is a 260-day ritual calendar of 13 numbers and 20 named days. The Haab’ is a 365-day year of 18 months of 20 days plus 5 extra Wayeb’ days. Together they form the 52-year Calendar Round.
Why does the converter show a Julian calendar date?+
Historians and archaeologists normally quote dates before October 1582 in the Julian calendar. For a Classic-period inscription the Julian date is a few days different from the proleptic Gregorian date, so both are shown.