Spider-Man: Homecoming kicked off with a flashback to Adrian Toomes and his crew cleaning up New York shortly after the Chitauri attack in The Avengers. After being fired by the government courtesy of Tony Stark's decision to form Damage Control, we then caught up with the character when he'd become The Vulture in the present day "8 Years Later." Fans quickly noticed the error made there.
After all, the Marvel Cinematic Universe is supposed to play out in real-time and that would mean that Spider-Man: Homecoming took place in 2020 rather than 2017. During a recent interview/trivia session to promote Avengers: Infinity War (which you can check out in the player below), Joe Russo was asked, "What was the time gap between the events of Avengers and Spider-Man: Homecoming?"
"Oh, it was eight years, I believe," he replied. "And it was quite controversial," the interview noted before Russo added: "Yes, it was a very incorrect eight years." The filmmaker doesn't elaborate on how much time really passed and he fails to address how the mistake will be dealt with (it probably won't) but it's clear now that even those working for Marvel realised they dropped the ball here.