You can see in a camera the date "March 22nd, 1986," which is the same day as Will Byers' birthday, but none of the characters remember it.
When Max and Dustin arrive at the video store, the sun is setting. When they walk in, it's mid-day outside.
When the teens are looking up the rental histories of the Ricks, Teen Wolf is shown as G rated, it was actually PG.
The type of rolling luggage that Mike brings to California wasn't invented until 1987.
The episode takes place in March, but Sadie is seen watching 'Misfits of Science'. The show was canceled in February of 1986 and never ran in March.
The mascot for the school is portrayed as the Hawkins Tigers but there is a mural on the outside wall of the school that reads "Go Eagles"
When Hopper is hosed down in chilly Kamchatka prison in Russia, there is writing in English above him on the wall..
Why would Murray disguise the location of Joyce's call to Enzo? He already knows her address since he had sent the package with the doll to her house.
Hopper has been detained by Russian soldiers within the tunnel complex under the mall in Indiana. Somehow they transport him from mid-west USA to the Russian Far East (Kamchatka) where he is imprisoned.