The Battle of Hogwarts takes place on 2 May 1998 in the Harry Potter books.
The battle is the decisive final confrontation between Voldemort’s forces and the defenders of Hogwarts. It occurs during Harry Potter and the Deathly Hallows after Harry returns to the school seeking the remaining Horcruxes.
The fighting causes major destruction and many deaths, including the deaths of Fred Weasley, Remus Lupin, and Nymphadora Tonks. Harry ultimately faces Voldemort in the Great Hall and defeats him.
The date is often confused with 31 October 1981, the night Voldemort attacked Harry’s parents. That earlier event begins Harry’s personal story, while 2 May 1998 marks the end of the Second Wizarding War.