Sontaran martial year

The Sontaran martial year was a unit of time alternative to Earth years, used by the Sontarans.

In the Sontaran martial year 5709, the Fifth Doctor interfered in the Sontaran's conflict with the Rutans on Samur. (AUDIO: Heroes of Sontar) As Styre's torture reports are known, this is sometime after the year 16087 (TV: The Sontaran Experiment) but it is unclear how the Sontaran calendar directly relates to the human Anno Domini calendar.''