The winal is the second unit of the Maya Long Count, equal to twenty kins, or twenty days, the same twenty-day period that structures the months of the Haab. The Long Count reckons time by stacking these units, each larger one a multiple of the last: twenty kins make a winal, and eighteen winals make the next unit up, the tun. That figure of eighteen, rather than twenty, is the single deliberate break in the otherwise base-twenty scheme, chosen so that the tun of 360 days stays close to the solar year. A Long Count date names how many of each unit have elapsed since the mythic starting point. These are the features of the Maya Long Count, the linear calendar the Classic Maya carved on their monuments to anchor events in an unbroken tally of days.
A Winal is twenty Kin, twenty days, the second place in the Long Count. Twenty is the base of Maya vigesimal counting generally, reflecting a finger-and-toe counting system, and the Winal is the one place in the Long Count where that base-20 logic applies without modification; the place above it, the Tun, breaks the pure vigesimal pattern deliberately. Eighteen Winal make one Tun rather than twenty, a substitution epigraphers read as a deliberate accommodation to the solar year: eighteen Winal of twenty days each gives 360 days, a round number close enough to the 365-day solar year that the Tun functions as an approximate year-count for Long Count arithmetic even though the Maya tracked the true 365-day year separately through the Haab. A Long Count date's second-place digit therefore never exceeds seventeen before rolling the Tun place over, exactly as the Kin digit never exceeds nineteen before rolling the Winal place over.