Based on various clues, the film takes place around 1994: 1984 is ten years earlier, 2029 is 35 years later, etc. It can't be later than 1994, because the Terminator refers to things happening in three years that happened before August 1997. If you pause on the police car computer screen showing John's information, you will see that he was born in February of 1985 (consistent with the first film) and is ten years old. So John Connor is ten years old in a year when he should be nine, and is being played by an actor who was more like thirteen at the time. John also says he will meet his father when he is 45, but in 2029 he should only be 44.