A specific instant in time, chosen as the point of reference or zero value of a system that involves identifying instants of time.
A geochronologic unit of hundreds of thousands to millions of years; a subdivision of a period, and subdivided into ages (or sometimes subepochs).
A particular period of history, or of a person's life, especially one considered noteworthy or remarkable.
A notable event which marks the beginning of such a period.
One complete presentation of the training data set to an iterative machine learning algorithm.
To divide (data) into segments by time period.
One day of sidereal time; the time in which Earth rotates once around its axis, relative to the point of the vernal equinox (about 23 hours, 56 minutes, 4 seconds).
The rotational period of Earth; the time in which Earth rotates around its axis 360 degrees.