The International Commission on Stratigraphy (ICS) has a long-standing tradition of producing international charts that define the higher-order divisions of geological time and provide absolute numerical ages for their boundaries. The primary objective of the ICS is to establish a global standard set of time-correlative units (Systems, Series, and Stages) for stratigraphic successions worldwide. These units form the basis for the Periods, Epochs, and Ages of the Geological Time Scale. The ICS Chart, first introduced at the 34th International Geological Congress in 2012, is a hierarchical structure of chronostratigraphic units that includes calibrated numerical ages for unit boundaries, serving as the International Geological Timescale. It caters to a wide range of users, from geologists to students and the general public, and is used for linking regional-scale divisions and for educational purposes. The ICS Chart is organized into four columns, with three columns dedicated to the Phanerozoic and one to the Precambrian. The Phanerozoic columns display 34 + 34 + 32 stages, while the Precambrian column is sub-divided to the system level. The chart visually represents the irregular division of geological time, with thicker intervals for stages of greater temporal duration. The numerical ages for boundaries are determined using various geochronologic techniques, and the chart includes GSSPs (Global Boundary Stratotype Sections and Points) to define the lower boundaries of units. The ICS Chart is regularly updated, with the latest version released in January 2013. It includes revised numerical ages for some stage boundaries, particularly in the Permian and Triassic periods, based on new high-precision radiometric ages and biostratigraphical calibrations. The ICS Chart is available in multiple languages and is available on the ICS website, which serves as the permanent archive of international geostandards. The ICS Chart and GSSP Table are updated annually or more frequently to reflect changes in numerical ages and the addition of new GSSPs.The International Commission on Stratigraphy (ICS) has a long-standing tradition of producing international charts that define the higher-order divisions of geological time and provide absolute numerical ages for their boundaries. The primary objective of the ICS is to establish a global standard set of time-correlative units (Systems, Series, and Stages) for stratigraphic successions worldwide. These units form the basis for the Periods, Epochs, and Ages of the Geological Time Scale. The ICS Chart, first introduced at the 34th International Geological Congress in 2012, is a hierarchical structure of chronostratigraphic units that includes calibrated numerical ages for unit boundaries, serving as the International Geological Timescale. It caters to a wide range of users, from geologists to students and the general public, and is used for linking regional-scale divisions and for educational purposes. The ICS Chart is organized into four columns, with three columns dedicated to the Phanerozoic and one to the Precambrian. The Phanerozoic columns display 34 + 34 + 32 stages, while the Precambrian column is sub-divided to the system level. The chart visually represents the irregular division of geological time, with thicker intervals for stages of greater temporal duration. The numerical ages for boundaries are determined using various geochronologic techniques, and the chart includes GSSPs (Global Boundary Stratotype Sections and Points) to define the lower boundaries of units. The ICS Chart is regularly updated, with the latest version released in January 2013. It includes revised numerical ages for some stage boundaries, particularly in the Permian and Triassic periods, based on new high-precision radiometric ages and biostratigraphical calibrations. The ICS Chart is available in multiple languages and is available on the ICS website, which serves as the permanent archive of international geostandards. The ICS Chart and GSSP Table are updated annually or more frequently to reflect changes in numerical ages and the addition of new GSSPs.