Time scales, their users, and leap seconds

@article{Seidelmann2011TimeST,
  title={Time scales, their users, and leap seconds},
  author={P. Seidelmann and John H. Seago},
  journal={Metrologia},
  year={2011},
  volume={48},
  pages={S186 - S194}
}
Numerous time scales exist to address specific user requirements. Accurate dynamical time scales (barycentric, geocentric and terrestrial) have been developed based on the theory of relativity. A family of time scales has been developed based on the rotation of the Earth that includes Universal Time (specifically UT1), which serves as the traditional astronomical basis of civil time. International Atomic Time (TAI) is also maintained as a fundamental time scale based on the output of atomic… 

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