Mesoamerican Long Count calendar 18. Thus 0.0.1.0.0 does not represent 400 days, but rather only 360 days and 0.0.0.17.19 represents 359 days. The name "b'ak'tun" was invented by modern scholars. The numbered Long Count was no longer in use by the time the Spanish arrived in the Yucatán Peninsula, although unnumbered k'atuns and tuns were still in use. Instead the Maya were using an abbreviated Short Count. Long Count dates are written with Mesoamerican numerals, as shown on this table. A dot represents "1" while a bar equals "5". The shell glyph was used to represent the zero concept. The Long Count calendar required
Adoption of the Gregorian calendar is only occasionally used today. North Korea from 1997 officially counts years based on the Juche era, the first year of which is 1912. The Republic of China (ROC) formally adopted the Gregorian calendar at its founding on , but China soon descended into a period of warlordism with different warlords using different calendars. With the unification of China under the Kuomintang in October 1928, the Nationalist government decreed that effective the Gregorian calendar would be used. China retained the Chinese traditions of numbering the months and a modified Era System, backdating the first year of the ROC to 1912;