In the scene where Rosemary is telling her doctor she knows that her husband along with neighbors are witches. She relates all the the things she has seen. She said she was to meet her friend hotch, just before xmas. He didn't show up because they had put him in a coma. And he died 3 mos. later. That would have been march yet at his funeral it looks very early summer or at least late spring. Not march in New York City. Her baby was due in June, and it happens soon after. couldn't have been 3 mos more like 5 or 6 .