Day 1: A letter to Harry Potter
Day 2: A letter to Ron Weasley
Day 3: A letter to Hermione Granger
Day 4: A letter to Draco Malfoy
Day 5: A letter to Neville Longbottom
Day 6: A letter to Ginny Weasley
Day 7: A letter to Luna Lovegood
Day 8: A letter to the Weasley Twins
Day 9: A letter to Cedric Diggory
Day 10: A letter to the character of your choice
Day 11: A letter to Albus Dumbledore
Day 12: A letter to Minerva McGonagall
Day 13: A letter to Rubeus Hagrid
Day 14: A letter to Remus Lupin
Day 15: A letter to Severus Snape
Day 16: A letter to Alastor Moody
Day 17: A letter to Argus Filch
Day 18: A letter to Sybill Trelawney
Day 19: A letter to Lord Voldemort
Day 20: A Letter to J.K. Rowling