Tun (Maya) (tun)

MayaHistorical unit (no longer in standard use)

18 winals or 360 days, the Maya 'year' of the Long Count.

1 tun (Maya) = 31,104,000 seconds (exactly).

About the tun (Maya)

Eighteen winals, or 360 days, make a tun. Scholars often call it the Long Count year, but it is five days shorter than the 365-day civil year, the haabʼ, and about five and a quarter days shorter than the tropical year of roughly 365.24 days. The tun therefore drifts away from the seasons, and the Maya tracked the solar year separately with the haabʼ.

The tun is the third position from the right in a written Long Count date. Its choice of 18 winals is the reason the system is not purely base-20: a strict base-20 count would have given 400 days at this step. The rounded 360-day figure is close to a year while staying a multiple of 20, which suited arithmetic on 20-day units.

The tun is the building block of the longer cycles. Twenty tuns form a katun, and rulers and events were frequently dated by how many tuns had passed. In seconds it equals 31,104,000, about 0.99 of a modern calendar year.

Sources: Wikipedia: Maya calendar; Wikipedia: Mesoamerican Long Count calendar; Steve Morse: Mayan Calendar Rules

Tun (Maya) conversion chart

1 tun (Maya) expressed in every other time unit:

More Maya units

• kin (Maya) (time)
• winal (time)
• katun (time)
• baktun (time)

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