21st century

In calendars based on the Christian Era or Common Era, such as the Gregorian calendar, the 21st century is the current century, as of this writing. By some interpretations, it lasts from 2001 to 2100, and the 3rd millennium lasts from 2001 to 3000. This is based on the argument that there was no Year Zero, so the first century began in year 1 http://www.astronomyboy.com/millennium/. However, common usage often regards the 21st century as lasting from 2000 to 2099. In 2000 the ISO implicitly backed this common usage by creating a calendar that incorporates a Year Zero (see 20th century). Decades are almost always considered as starting with the "0" year and named accordingly ("2010s", etc.), so the first decade of a century could overlap back into the preceding one.

Related Topics:
Calendar - Christian Era - Common Era - Gregorian calendar - Century - 2001 - 2100 - 3rd millennium - 3000 - First century - 1 - 2000 - 2099 - ISO - 20th century

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Similar to the 20th century's place in popular culture as part of names such as 20th Century Fox, the 21st century has been used in the names of a number of companies and organizations. The real estate firm Century 21 uses a name that now refers to this century.

Related Topics:
20th century - 20th Century Fox - Century 21

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