20 July

20 July 1966 was the day that the First Doctor started travelling with Polly and Ben — and the day the Second Doctor stopped. Though it was an apparent accident, it was nevertheless the first occasion on which the Doctor was able to both pick up his companions on the same date and at the same city to which he ultimately returned them. (TV: The War Machines, The Faceless Ones)

Three years later, Apollo 11 landed on the Moon and Neil Armstrong became, as far as the majority of humanity was aware, the first man to walk on the Moon. (TV: Day of the Moon, PROSE: Who Killed Kennedy)

The Eleventh Doctor interfered with the transmission of the Moon landing with the help of the former FBI agent Canton Delaware. At the crucial moment that Armstrong set foot on the Moon, they inserted footage of a Silent ordering for its kind to be killed on sight. (TV: Day of the Moon)

In 1970, another Moon landing took place, with the First Doctor, John, and Gillian watching on the Moon. (COMIC: Moon Landing)