Arnold drives Charlotte home from the hospital in a snowstorm, when plenty of snow already covers the ground. At the film's conclusion, it's New Year's Eve and Charlotte mentions that she's been home for 3 months, which means that the snowstorm happened at the end of September.
(at about 17 mins) While Charlotte is in bed, the clock on the nightstand shows just after 8:00, which makes sense given that she goes downstairs and wishes everyone good morning just before breakfast. However, the clock tower bell in the distance can be heard to ring several more times beyond eight clangs.
At the end of the scene outside R.H. Sterns in Boston, camera shadow falls across Charlotte, Inez, and Hazel as they walk away.
At the Christmas party Charlotte introduces herself as "Joan", and, even though Arnold later berates her for trying to look like Joan, there is never any mention of her calling herself by the name.