The movie is set on the present day (2003/2004), and if the young Carolina is supposed to be 30 years younger than her mature self she would be living in 1973/1974. Instead, her younger self is clearly living in the 1960's, judging from the dresses she wears, the hair-style she uses and the historical events surrounding the story. The filmmakers were probably aware of this, but chose the 1960s because it's widely considered a far more interesting period in Brazilian history than the 1970s.