 While Christie's novels are set contemporaneously with the time of writing (between the 1920s and 1970s), 1936 was chosen as the year in which to place the majority of "Poirot" episodes; references to events such as the Jarrow March were included to strengthen this chronology.With some exceptions, the series as a whole is set in roughly chronological order between 1935 and 1939, just prior to the Second World War.All episodes from series 1–5 are 50 minutes long, except where marked as "feature-length".