After installation a few weeks ago, an "Apple loves Singapore" mural covering work on the flagship outlet has been adorned with an opening date —May 27. Workers added the opening date overnight to the Knightsbridge shopping. REUTERS/Brendan McDermid WASHINGTON — The U.S. government on Tuesday urged a federal judge to reject the February court date sought by AT&T and Time Warner in a dispute over the firms’ proposed merger, arguing…