Millennium

Millennium is a period of 1,000 years. The word comes from the Latin mille, meaning thousand, and annus, meaning year, and it has long been used to denote a sizable span of time in historical, religious, and scholarly contexts.

In calendar usage, history is often organized into millennia. The commonly accepted framework states that the 1st millennium AD runs from year 1 to 1000, the 2nd from 1001 to 2000, and the 3rd from 2001 to 3000. There is no year zero in the Anno Domini system, which affects how boundaries between millennia are calculated in strict historical terms.

In scientific and geologic contexts, millennium can be used to describe a 1,000-year interval, but more precise measures such as kiloannum (ka) are preferred for dating and timing in disciplines like geology, archaeology, and astronomy.

In theology, especially within Christian eschatology, the Millennium refers to a prophesied thousand-year reign of Christ mentioned in the Book of Revelation (chapter 20). The term is associated with three primary interpretive frameworks: premillennialism (Christ returns before the millennium), amillennialism (the Millennium is symbolic or spiritual rather than a literal future era), and postmillennialism (Christ returns after the millennium).

In contemporary usage, “millennium” appears in cultural and political contexts, such as the turn of the millennium around the year 2000. It also appears in institutional phrases like the Millennium Development Goals, launched in 2000 by the United Nations and later replaced by the Sustainable Development Goals. The adjective millennial is used for people born around the late 20th century to the early 1990s and for related cultural phenomena.