A notable event which marks the beginning of such a period.
A geochronologic unit of hundreds of thousands to millions of years; a subdivision of a period, and subdivided into ages (or sometimes subepochs).
A specific instant in time, chosen as the point of reference or zero value of a system that involves identifying instants of time.
A particular period of history, or of a person's life, especially one considered noteworthy or remarkable.
One complete presentation of the training data set to an iterative machine learning algorithm.
To divide (data) into segments by time period.
The opening sequence of any event.
The opening kick of each half of a game of football.
The opening sequence of notes in a song, usually played by the song's main instrument, to indicate the beginning of the song.