Though the victory parade would have taken place after the armistice in November, 1918, it is bright and sunny and people are dressed for warm weather.
In an early sequence, set in 1918, Constance Bennett is shown playing a phonograph record on the Victor label - but the label is the "scroll design" Victor didn't use until 1925.
Although the story takes place during World War, 1917-1918, and the years immediately thereafter, all of Constance Bennett's clothing and hairstyles are strictly from 1931, as are also those of the women extras and passersby.
Toward the end of the movie, we see only Doris' shadow on the wall as she goes to her son's crib to get him. Just before the scene cuts, we see the shadow of two hands rising up from behind the crib. They are probably the hands of the director giving visual signals to Constance Bennett for her movements in the scene.