Monday

Monday was a day of the week.

Trends
Bank holidays were usually held on Mondays. (TV: The Idiot's Lantern, The Rings of Akhaten)

Sergeant Paterson taught physical fitness to older men on Mondays. (TV: Survival)

The Smudgelings got together on Mondays. (PROSE: Mad Dogs and Englishmen)

Gita Chandra once jokingly asked Sarah Jane Smith whether she saved the world every day, "or is it just on Mondays?" (TV: The Day of the Clown)

History
Clara Oswald faced a Skovox Blitzer "on a miserable wet Monday morning." (TV: The Caretaker, COMIC: Terrorformer)

The Judoon put Gloucester into lockdown on a Monday in 2020, in order to hunt down the Doctor, who was in hiding under a Chameleon Arch as "Ruth Clayton". (TV: Fugitive of the Judoon)

The Royal Hope incident took place on a Monday, three days prior to the 2008 United Kingdom general election. (PROSE: The Time Traveller's Almanac)

Behind the scenes
Episodes of The Sarah Jane Adventures typically aired in the UK on Mondays and Tuesdays. Gita Chandra's aforementioned joke to Sarah Jane about only saving the Earth on Mondays may have been a reference to the former.