<P> The geologic time scale (GTS) is a system of chronological dating that relates geological strata (stratigraphy) to time . It is used by geologists, paleontologists, and other Earth scientists to describe the timing and relationships of events that have occurred during Earth's history . The table of geologic time spans, presented here, agree with the nomenclature, dates and standard color codes set forth by the International Commission on Stratigraphy (ICS). </P> <P> The primary defined divisions of time are eons, in sequence the Hadean, the Archean, the Proterozoic and the Phanerozoic . The first three of these can be referred to collectively as the Precambrian supereon . Eons are divided into eras, which are in turn divided into periods, epochs and ages . </P>

The time interval that began with the formation of earth is called