Warner Bros. Pictures today moved back the release date of Harry Potter and the Half-Blood Prince to day-and-date domestically and in the major international markets on
July 17, 2009.
Studio boss Alan Horn cited "repercussions of the writers’ strike, which impacted the readiness of scripts for other films -- changing the competitive landscape for 2009 and offering new windows of opportunity that we wanted to take advantage of. We agreed the best strategy was to move Half-Blood Prince to July, where it perfectly fills the gap for a major tent pole release for mid-summer.” Apparently, the move was subordinate Jeff Robinov's idea. But he confirmed that the release date change does not alter the production schedule for the two-part Harry Potter and the Deathly Hallows.
Original release date was November 21, 2008.