15 December is the 349th day of the year (350th in leap years). There are 16 days remaining.
- 1992: Hermione Granger continues brewing a Polyjuice Potion in Moaning Myrtle's Bathroom. 
Behind the scenes
- 1969: Ralph Ineson, the actor who plays Amycus Carrow, is born.
- 1992: Alexander Watson, who played an Extra in the first two Harry Potter films, born.
- 2012: The Harry Potter Shop at Platform Nine and Three-Quarters opens to the public at King's Cross Station in London, England.