eleven o'clock on Saturday
`` And I have not been obliged to stoop once , to clear away the tiresome bits , the whole week through , '' thought Otto contentedly . `` But who can have done all this dirty work without being obliged to do it ? '' Now he determined , for once and all , to have that question settled . The school hours ended at eleven o'clock on Saturday . Otto waited until all the children had gone , and the room was empty . Then he went outside , closed the door , and leaned with his back against it . There could no one enter without his seeing who it was .