13 September

13 September was a date.

Events
At some point in the 1970s or 1980s, the Third Doctor and Jo Grant were looking after Sir Reginald Styles' house when they were held captive by Anat, Boaz and Shura, who mistook the Doctor for Styles, whom they blamed for the Dalek invasion in the alternate 22nd century and planned to murder him in order to restore their version of the timeline. In an attempt to escape, Jo accidentally activated the Guerilla's time machine and transported herself to the 22nd century and, after an attack by the Daleks' servants, the Ogrons, the Doctor, Anat and Boaz soon followed her. (TV: Day of the Daleks)

Other
13 September 1752 was the eleventh and final day purchased by Faction Paradox through the Gregorian Compact for their Eleven-Day Empire. (PROSE: Interference, The Book of the War) A guide for time travellers' entry for 13 September acknowledged the skipping of eleven days. (PROSE: Time Traveller's Diary)