Ticketmaster issued a press release

Ticketmaster issued a press release confirming that "due to the sheer magnitude of the 'This Is It' concerts at the O2 Arena promoters and producers AEG Live and Kenny Ortega, Michael’s directorial partner and creative collaborator have elected to move back a few of the opening shows in order to meet the challenges presented by such a massive and technically complex show. Organisers are determined that all Michael’s legions of fans attending the opening nights get the same quality of staging and level of entertainment..."

The dates affected include: July 8th, 2009 (moved to July 13th, 2009), July 10th, 2009 (moved to March 1st, 2010), July 12th, 2009 (moved to March 3rd, 2010), and July 14th, 2009 (moved to March 6th, 2010). No other dates are affected by the rescheduling.

Continuing on, the statement reads: "Kenny and Michael are, at the same time, both creative pioneers and perfectionists. This show has grown in size and scope, thereby, necessitating more lead time for manufacture of the set, programming the content for the massive video elements, and, most importantly, more time for full production and dress rehearsals in the world’s busiest arena, the O2. As much as we agonized over this change in the original schedule, we are sure the fans will understand when they experience the level of entertainment Michael Jackson intends to deliver while also ensuring the safety of the musicians, cast and crew and the crisp execution of the production. It is AEG Live’s sincere hope that those lucky enough to have purchased tickets will have enough time to change their personal schedules and travel plans if they are coming from outside of London. We do not want anyone to miss this once-in-a-lifetime experience...Michael, who is directly involved with all aspects of the styling/choreography/band selection and rehearsals, is working around the clock to ensure this is the show to end all shows! Kenny Ortega, Michael’s directorial partner and creative collaborator said, 'After directing the Dangerous and HIStory tours, I know what the fans expect and myself and the team want to deliver a flawless production. We apologise to all disappointed Michael Jackson fans and remain extremely dedicated and focused on creating an exceptional live music experience.'"