26 February

26 February was a date.

In 1935, the first ever radar test took place at Daventry. According to the Seventh Doctor, the British did not yet have access to radar at that point and this day simply marked "the first time that a radar echo was ever detected." (PROSE: Just War)

In 2085, the first official contact between humans and an extraterrestrial intelligence occurred. (PROSE: Time Traveller's Diary)