ten minutes to seven
`` Hit 's edzactly seven -- '' His back was to the official . `` Humph ! '' grunted the clerk . `` Do n't you know -- '' `` -- lackin ' six -- '' `` -- the sun sets at ten minutes to seven ! '' `` -- lackin ' sixteen minutes forty-two seconds and a quarter , '' pursued Robin , with head bent as if he were looking at a watch . `` Oh , you be hanged ! Your old watch is always slow . ''