"....you missed the last Quidditch match, we were steamrollered by Ravenclaw without you...."
-- Ron Weasley to Harry (PS17)
Following his struggle with the Voldemort-possessed Professor Quirrell, a battered Harry Potter is unconscious in the Hospital Wing for three days. Because of this, he missed the last Quidditch match of the 1991-92 school year, against Ravenclaw. There was no alternative Seeker for the Gryffindor team with Harry out, so they were beaten by a large margin (PS17).
A guess based on the real world calendar and other events in the book, the last Quidditch match of the season takes place at the beginning of June, after the yearly exams but before the end of term feast.
From the Web
WizardingWorld.com (Pottermore) features:
- Things you might not know about Quidditch
- Ranked: the best and worst Hogwarts Quidditch players
- Ultimate Quidditch Quiz
- How to survive a Quidditch match
Harry Potter Wiki: Quidditch