Maya calendar the land of Yucatán into 13 'kingdoms'. 1897 text by Cyrus Thomas Maya calendar The Maya calendar is a system of calendars used in pre-Columbian Mesoamerica and in many modern communities in the Guatemalan highlands, Veracruz, Oaxaca and Chiapas, Mexico. The essentials of the Maya calendar are based upon a system which had been in common use throughout the region, dating back to at least the 5th century BCE. It shares many aspects with calendars employed by other earlier Mesoamerican civilizations, such as the Zapotec and Olmec and contemporary or later ones such as the Mixtec and Aztec calendars. By
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