Voldemort Day

Voldemort Day was a holiday observed in an alternate reality in which Harry Potter was killed during the Battle of Hogwarts and Lord Voldemort won the Second Wizarding War.

This alternate universe was created by Albus Potter and Scorpius Malfoy travelling back in time to change the outcome of the second task of a Triwizard Tournament. When Scorpius returned to the year 2020, he was found by Dolores Umbridge, who, in the new, changed timeline, was headmistress of Hogwarts. Scorpius asked about Albus and Umbridge told him there hadn't been a Potter at Hogwarts since Harry died many years ago. She ordered him to return to the castle at once because it was Voldemort Day and she didn't want him to spoil it.