Billboard reports that Canadian singer/songwriter Daniel Powter earned his first No. 1 on the U.S. pop singles chart Thursday as ‘Bad Day’ climbed one rung to the summit, swapping places with reggae star Sean Paul’s ‘Temperature’. His international hit had been languishing in the United States until ‘American Idol’ started playing ‘Bad Day’ every week, as underscore music to the video of the departing contestants on results shows.