Complex sentence: The world premiere took place July 23,2008, at Grauman's Chinese Theatre in Hollywood; the UK premiere was held on July 30,2008, in London's Empire, Leicester Square.
Split into simpler sentences: The world premiere took place on July 23,2008, at Grauman's Chinese Theatre in Hollywood. The U.K. premiere was held on July 30,2008, in London's Empire, Leicester Square.