Avengers: Endgame spoilers ahead. One of the biggest unknowns from the Avengers: Endgame trailers is when the movie takes place. Clearly, some time had passed as evidenced, in part, by some surprising hairstyles: Hawkeye has a mohawk, and Black Widow has a new red and blonde look. This, along with other clues, got fans guessing that Avengers: Endgame would have a time jump, and now that the movie is out, we know exactly what ended up happening.
There is a time jump in Endgame and it shows the Avengers going five years into the future. (Well, before they go what would then be about 10 years into the past, but we'll get to that.)
The movie opens right where Avengers: Infinity War left off, with half of the living creatures in the universe disappearing thanks to Thanos. Obviously, the remaining Avengers don't just give up after this, so with Nebula's knowledge of where her father would go and Rocket's ship, they head off to find Thanos, get those stones, and try to reverse everything.
This all happens very quickly, which is a clear sign in a three hour movie that things aren't going to go smoothly. The Avengers find Thanos, but he's already used the stones to destroy the stones. An angry Thor chops Thanos' head off, killing him, and then it happens: "Five years later" shows up on the screen.
Yep, the Avengers lived in a world where half of the population was gone for five years before a new development allowed them to really get down to business. While Captain America was leading support groups and Black Widow was manning the fort at Avengers HQ, Scott Lang (aka Ant-Man) returned from the Quantum Realm to find that the world was completely different than when he'd left it. And while five years had passed, it felt to him like hardly any time at all. Hmm... Sounds like going into the Quantum Realm could be useful for stopping Thanos. Ta-da! It's time traveling time!
And while the heroes are getting ready to go back in time, we find out what a couple of the other Avengers have been up to during their five-year hiatuses. Tony Stark is living the quiet life with Pepper Potts and they have a young daughter. Bruce Banner has found balance in his life and is now always a combo of Bruce and Hulk. Thor has become obsessed with video games, eats pizza and drinks beer all day, and has a very different hairstyle, too, but the trailer didn't spoil that big reveal.
As for what else has been going on in the past five years? Well, optimistic Captain America lets us know that Thanos' finger snap had an effect on the Earth's ecology, because there's now whales in the Hudson River due to the water being cleaner. But also, billions of people died as shown in huge memorial grounds for "The Vanished". (Also, half of the whales would have disappeared in this, too, so, just keep that in mind, Cap.)
It's not long before we leave this time period, though. Thanks to Ant-Man's knowledge of the Quantum Realm and Iron Man's knowledge of literally everything, the Avengers travel back in time to try to gather the Infinity Stones before Thanos.
So, yeah, there's a lot of time jumping in this movie. But for any fans who guessed from the trailer that there would be a jump to the future, you were right. You deserve a pat on the back and one of the coldest beers in Asgard.