An eight month-delay has just been shortened…by two days.

After repositioning Harry Potter and the Half-Blood Prince to open on July 17, Warner Bros. has changed its mind again. The film, once scheduled for a November 2008 release, will now open on July 15.

Why? The studio just likes to get a jump start on those earnings.  (Order of the Phoenix also opened on a Wednesday back in 2007.)

Meanwhile, a date for the future Harry Potter film can now be penciled in as well: July 15, 2001. That’s also the slot tentatively set aside for Paramount’s The Avengers. Since the day chosen is not a Wednesday, I’m guessing someone will be doing some tinkering in about a year from now.