The Age of the Universe
  Globular clusters are the oldest objects in the Galaxy whose age may be accurately determined. As such globular cluster ages provide the best estimate for the age of the universe. The age of a globular cluster is determined by a comparison between theoretical stellar evolution models and observational data. Current uncertainties in the stellar models and age dating process are discussed in detail. The best estimate for the absolute age of the globular clusters is $14.6\pm 1.7\,$Gyr. The one-sided, 95\% confidence limit on the lower age of the universe is $12.2\,$Gyr. 
Brian Chaboyer (CITA)