This story occurs an unspecified time after Dunkirk.
The episode introduces Wilson's Daughter only known as the Wren, a daughter from a previous relationship thus making her Private Pike's half sister
The calendar with the photograph of London's Trafalgar Square hanging in Jones' shop shows the 4th of June as being on a Sunday: This occurred in 1939 and in 1944. As the war didn't start until September '39 and Dunkirk had already been referenced, this dates the episode to 1944, assuming Jones kept his calendar "up to date".