Sunday

Sunday was a day of the week.

Opinions
The Doctor's tenth incarnation claimed to never land on Sundays, calling them "boring". (TV: Silence in the Library) His eleventh incarnation listed Sundays in his list of "boring stuff", along with Tuesdays and Thursday afternoons. (TV: The Impossible Astronaut) Ace similarly expressed her dislike for the day, calling it "the one day of the week you can't even get a decent television programme". (TV: Survival) She later said Kirith was as exciting as Sunday morning's telly. (PROSE: Timewyrm: Apocalypse)

When the Fourth Doctor informed his other incarnations that the Earth was facing "the greatest peril in its history", the Fifth and Seventh Doctors suggested it was Tuesday, to which the Ninth Doctor reminded them not to forget Saturdays, with the Thirteenth Doctor adding "and Sundays now". Upon hearing this, the Tenth Doctor queried "it happens on a Sunday as well now?" (WC: Doctors Assemble!)

Trends
Sunday school took place on Sundays. (TV: The Evil of the Daleks, PROSE: The Eleventh Tiger)

Football games were often on Sundays. (PROSE: Head of State)

Another event that frequently took place on Sundays was referred to as "Sunday roast." (TV: The Girl in the Fireplace)

On Sundays, Mary McGinty would work in "the newsagent". (TV: Turn Left)

History
3 September 1939, the day the United Kingdom and France declared war on Nazi Germany at the start of World War II, fell on a Sunday. (PROSE: Timewyrm: Exodus, AUDIO: A Blind Eye) 30 June 1940, the day the Germans occupied Guernsey, was also a Sunday. (PROSE: Just War) 7 December 1941, the day Japan attacked Pearl Harbor during the Pacific War, bringing the United States into the conflict, was a Sunday as well. (PROSE: Only Connect)

The Apollo 11 mission to the Moon landed on Sunday 20 July 1969. (PROSE: Blue Moon)

On 21 December 1981, Commander Bill Pollock told Sarah Jane Smith that George Tracey usually visited his mother in Cirencester on Sundays. (TV: A Girl's Best Friend)

The Seventh Doctor and Ace visited Ealing Broadway on a Sunday afternoon in July 1990. (PROSE: Cat's Cradle: Time's Crucible)

British Summertime began in early 2005 on a Sunday morning at 01:00am when the clocks went forwards. (PROSE: The Clocks Go Forward)

By Christmas 2006, Mickey Smith had dinner on Sundays at 48 Bucknall House with Jackie Tyler, who talked about her absent daughter, Rose Tyler, all afternoon. (TV: The Christmas Invasion)

On 10 May 2020, Petronella Osgood and the Zygon Osgood had a Zoom call titled "Zygons and Zoom", scheduled for 18:40 - 19:00, within which the Thirteenth Doctor contacted them. They then scrolled through BBC iPlayer and watched the Doctor Who Series 9 episode The Zygon Invasion. (WC: The Zygon Isolation)

Other references
When the First Doctor's TARDIS arrived in London in 2167, Ian Chesterton noted it was "pretty deserted", jokingly suggesting it was a Sunday. (TV: The Dalek Invasion of Earth) The Third Doctor made a similar joke to Sarah Jane Smith when they arrived in a similarly deserted London, this time in the 1970s, saying, "Great Britain always closes on Sundays." (TV: Invasion of the Dinosaurs) Donna Noble also inquired as to whether she and the Tenth Doctor had landed on a Sunday when they realised that there was "silence in the Library". (TV: Silence in the Library)

Behind the scenes
series 11 in 2018, regular weekly Doctor Who airings on BBC One moved from Saturday evenings to a Sunday teatime slot, in an effort to reach a wider audience. The Easter Special Legend of the Sea Devils aired on Easter Sunday in 2022, coinciding with the premiere episode of the audio series Redacted, which released weekly on Sundays from then on.