The U.S. National Grid — a major step forward
in metrication. To see how it works, click here.

Bureau International des Poids et Mesures

“The task of the BIPM is to ensure world-wide uniformity of measurements and their traceability to the International System of Units (SI).”

If you click on the link to the BIPM, you will be able to read about that organization, and you will also be able to check the international time.