User blog comment:LilyLovegood/ The films do not take place during the 90's/@comment-306173-20110410230940

Regardless of that, by putting the canonical dates all over their props, they have established the timeline as being in the 1990s. Of course, this is a work of fiction, so we could be talking of an alternate reality where by the 1990s there were already iPods, the Millennium Bridge, the London City Hall, etc, etc.