A wish said around the start of a new year to wish someone well for the New Year (holiday) or for the (entire) new year.

The holiday occurring on the last day of the year, December 31st.

the millennium bug

A year of the Common Era/Christian Era; anno Domini; numbered from the once estimated first year for the birth of Jesus Christ.

An annual holiday of several cultures that marks the beginning of a new year according to a lunar or lunisolar calendar, as opposed to a new year dictated by a solar calendar such as the Julian or Gregorian calendars.

The year 1816, in which severe climate abnormalities caused average global temperatures to decrease.

plural of one-year-old

plural of 100-year flood

A flood event that has a 1% probability of occurring in any given year; an exceptionally large flood.

A year that does not contain the day February 29.