4221

43K2.1 was the year during which the Doctor encountered the Walker Expedition on the planet Krop Tor. (DW: The Satan Pit)


 * The desgination 43K2.1 may refe to the year 43,231 CE. It might possibly refer to the year 4321 CE. We don't know when the Walker Expedition had left Earth or how long it had stayed on Krop Tor by the time its crew members met the DOctor.