Jim Morrison died in 1971, but according to the movie The Doors, he managed to break on through to the '80s. That's the only way to explain how he's wearing Ray-Bans, the quintessential sunglasses of the Reagan era.
In Dirty Dancing, which is set in the '60s, Baby is often seen wearing jean shorts, which weren't really a thing until the '80s. So maybe being 20 years ahead of her time fashion-wise is the REAL reason she had the time of her life.
In My Girl, the title character has a mood ring. The problem? The movie is set in 1972, and mood rings weren't invented until 1975. Maybe Vada can use her time travel powers to save Macaulay Culkin's character.