A millennium is a period of time equal to one thousand years . The term may implicitly refer to calendar millenniums; periods tied numerically to a particular calendar, specifically ones that begin at the starting point of the calendar in question or in later years which are whole number multiples of a thousand years after it.... (Millennial is the adjective to millennium.)
This article covers all forms of Christian and non-Christian Millennialism. You may be looking for the specific articles on Christian Premillennialism, Amillennialism or Postmillenialism....
Generation Y is a generational cohort which consists of those people born after the Generation X cohort. Its name is controversial and is synonymous with several alternative names including The Net Generation, Millennials, Echo Boomers, and iGeneration.... , aka the Millennials