Post Office – Newton Stewart, Kirkinner – Opening Hours & Branch Details Post Office is found in a good spot on Kirkinner, a 8.90 mile drive south of the centre of Newton Stewart (nearby Main Street). The branch is convenient for the people of Loch Head, Bladnoch, Wigtown, Carsluith, Kirkinner and Whauphill. Today (Friday), service starts at 9:00 am and continues until 5:30 pm. Please see the various sections on this page for specifics on Post Office Newton Stewart, Kirkinner, including the hours of operation, location description, customer rating and more information about the branch.