Corrected entry: When Celie is giving birth to Olivia it says Winter 1909. Later on in the movie when she is in the cloth store and thinks she sees her daughter, Olivia, it says Spring 1909.
Correction: No, in 1909 she gave birth to her son Adam. Olivia had already been born and given away.
Other mistake: Mister cooks Shug Avery a breakfast of grits, biscuits and ham, and takes it to her room. She throws the breakfast against the wall. The breakfast leaves a bright yellow and bright red stain on the wall. There was nothing on the tray that could have left those colors on the wall. (00:51:10)
Suggested correction: There absolutely were 2 things on the plate that would have left those colors. When you see the plate up close, you see a red sauce (presumably ketchup or tomato sauce) on the side of the plate, and the yellow comes from the yolks from the sunny-side up eggs he made for her (which he mentions it as he takes the tray into the room). Look more closely at the plate next time. Also, just because the clip mainly shows him TRYING to make grits and biscuits, doesn't mean he didn't make anything else to go with it. The plate he carries up shows several things he made (mostly burnt) but the red sauce was definitely on the plate as well as the eggs. So this is incorrect.
Correction: That's wrong. Adam was born first and taken while Celie was sleeping. Olivia is the second born.
It was probably in January (winter) 1909. However, if it was spring, the baby wouldn't be more than 5 months old.