Introduction: CCU half-day devoted to the second

J. Ullrich

IAU report to the CCU

N. Capitaine

URSI report to the CCU

Y. Koyama, G. Petit

IUGG report to the CCU

C. Boucher

ITU report to the CCU

R. Beard

Statement from CCTF President to CCU on the role of relativity in time & frequency metrology

N. Dimarcq

The SI second

N. Dimarcq, P. Tavella, G. Petit

Towards a redefinition of the second with optical clocks

S. Bize