- Fri, May 24
- Jim Broadbent's birthday
- Sophie Wehner's birthday
- Harry and Ron meet Aragog in Forbidden Forest
- Sat, May 25
- Katie Harrison's birthday
- Alec Hopkins's birthday
- Sun, May 26
- Will Dunn's birthday
- Helena Bonham Carter's birthday
- Detention in the forest; Quirrell drinks unicorn blood
- “That brings [Trelawney’s] total of real predictions up to two. I should offer her a pay raise. . . .”
- June 30, 2009 – The Harry Potter and the Half-Blood Prince video game is released in North America.
Did You Know
- There is a rumor that when the House Points Counter was built for the Harry Potter film series it caused a nation-wide shortage of Indian glass beads.