The voiceover at the end states that Gloria Morgan Vanderbilt died in 1964. She in fact died in February 1965.
In a voiceover exchange of 1933 telegrams Gloria states that she will be returning from Paris on the Lusitania arriving on Thursday September 25. The Lusitania was torpedoed in May 1915 and no subsequent liners were given this name, although her sister ship Mauretania was in her last year of service. September 25 1933 was also a Monday.
In the scenes in Central Park early in the film, the San Remo apartment house building is shown clearly in the skyline. The scene is set in 1922, but the building wasn't erected until 1929.