Mesoamerican Long Count calendar 20, 2012 (Gregorian Calendar), followed by the start of the 14th b'ak'tun, 13.0.0.0.0, on December 21, 2012. There are only two references to the current creation's 13th b'ak'tun in the fragmentary Mayan corpus: Tortuguero Monument 6, part of a ruler's inscription and the recently discovered La Corona Hieroglyphic Stairway 2, Block V. Maya inscriptions occasionally reference future predicted events or commemorations that would occur on dates that lie beyond 2012 (that is, beyond the completion of the 13th "b'ak'tun" of the current era). Most of these are in the form of "distance dates" where some Long Count date is given,
Adoption of the Gregorian calendar the Empire (except Scotland, which had already done so from 1600) changed the start of the civil year from 5 April to 1 January. Consequently, the custom of dual dating (giving a date in both old and new styles) can refer to the Julian/Gregorian calendar change, or to the start of year change, or to both. The British tax year traditionally began on Lady Day (25 March) on the Julian calendar and thus became 5 April, which was the "Old Style" equivalent. A 12th skipped Julian leap day in 1800 changed its start to 6 April. It was not changed