On 20 April, the following important behind-the-scenes events were known to have occurred:
- 1964 - BBC2, the United Kingdom's third TV network, was launched. Henceforth, the main BBC network, which aired Doctor Who, would be known as BBC1.
- 1967 - Location filming The Evil of the Daleks began at Grim's Dyke House. (TCH 10)
- 2002 - Recording for The Rapture took place at The Moat Studios.
- 2004 - Recording for The Juggernauts took place at The Moat Studios.
- 2010 - Recording for Escaping the Future took place.
- 2011 - Recording for Power Play took place at The Moat Studios.
- 2015 - Recording for The Shadows of Serenity and Prime Winner took place at The Moat Studios.
- 2016 - Recording for The Hesitation Deviation took place at The Moat Studios.
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