The Space Year was a dating system used by the human inhabitants of the planet Destination, denoting how many years had passed since their ancestors left their homeworld for outer space. The First Doctor, accompanied by Ian Chesterton, Barbara Wright and Susan Foreman, arrived on Destination on 3 March of the Space Year 2003. War between the Dalmari and humanoid colonists began in Space Year 2009. In Space Year 2015, the war was ended when the Master was exposed as playing both sides by the Doctor, who left when his TARDIS returned to him two years later. (AUDIO: The Destination Wars)
The Fourth Doctor recounted to Davros how a fleet from the planet Hyperon intercepted a Dalek invasion of Venus in Space Year 17,000. (TV: Genesis of the Daleks)