12 (number)

12 was a number.

According to Jo Grant, 108 divided by 9 was 12. Also according to her, 12 divided by 4 was 3. (TV: The Claws of Axos)

Clocks generally showed twelve hours. (TV: Doctor Who, The Time of the Doctor, The Pyramid at the End of the World) As a result, there was 12 o'clock midday, (TV: Children of Earth: Day Five, The Gathering) also 12 PM (TV: The Mind of Evil) or noon, bringing in the afternoon, (TV: Robot of Sherwood) and 12 o'clock midnight, (TV: Doctor Who) which ushered in the next day of the year. (TV: The Next Doctor, The Snowmen)

Earth years also had twelve months. (TV: World War Three, Last of the Time Lords)

Time Lords were allotted twelve regenerations in a life cycle.

As a result, the Ninth Doctor once accidentally brought Rose Tyler back home to London twelve months too late, rather than twelve hours as he had intended. (TV: Aliens of London)

The Eleventh Doctor, soon after regeneration, returned to Amelia Pond twelve years too late, and she had grown up into a woman. (TV: The Eleventh Hour)

When the Twelfth Doctor asked Clara Oswald to pick a two-digit number, she chose 12. He then asked the crew of the crew to look at the first word of page 12 of the book they were holding, as part of the Helman-Ziegler test. (TV: Last Christmas)

While trapped in his confession dial for 4.5 billion years, (TV: Hell Bent) the Twelfth Doctor left a message for himself to find room 12, and continually found his way there. That room contained an azbantium wall to Gallifrey, which he punched over and over again before dying to teleport himself back in. (TV: Heaven Sent)

The Twelfth Doctor once told Bill that "eleven plus two" was an anagram of "twelve plus one", to which Bill responded that both of these were equal to 13. (COMIC: Harvest of the Daleks)

James Clark Maxwell's investigations into electromagnetism took place twelve years prior to 1866. (TV: The Evil of the Daleks)