Bernard Guinot (b.1926), director of the Time Division at the International Bureau of Weights and Measures (BIPM), Paris. Guinot, known affectionately as insFather Timeins, has made two major contributions to accurate time keeping through atomic clocks. Guinot was the creator of International Atomic Clock Time (TAI), an average of the time given by a variety of atomic clocks throughout the world. He was also the leader of the group that has established the Universal Time Coordinate (UTC), which keeps the TAI in tune with the sometimes-irregular rotation of the Earth. The UTC system adds a 'leap second' to all atomic clocks once every two years.