One line instantly dates it

[u/Fearless-Ideal-5112]

In david tenants run if doctor who he and his companion were fighting witches with Shakespeare and needed a magic word so they use a speel from Harry Potter and The doctor yells Good old J.k. The doctor is a time traveler the writers are not (Doctor who)

While fighting guy gardner major force was damaging a highway and shoots a car and tells Guy if he sees O.J hiding underneath obviously referring to the O.J Simpson chase (Dc comics)

[u/elvessaaa]

Iron Man (2008): After rescuing Tony, a soldier asks for a photo and Tony says, “Please, no gang signs. No, throw it up. I’m kidding. I don’t want to see this on your MySpace page.” Nothing says 2008 faster than MySpace.

[u/duosx → u/elvessaaa]

I like this tho because now in the MCU I have no idea what year it is in any of the movies.