An ABC spokesperson told the site:
ABC TV has scheduled the new series of Doctor Who to screen Saturdays at 7.30pm on ABC1, which we believe is the best slot to reach the family audience. (We are) not able to broadcast Doctor Who until after it screens in the UK. So, in anticipation that the BBC will launch the new series over Easter in the UK, we have scheduled the series to start the following weekend.
The BBC have yet to reveal when The Impossible Astronaut will premier in the UK - this is likely to be confirmed in a week's time via the Press Office's Programme Information Page, if not sooner.