Warning: SPOILERS for WandaVision episode 4.
It was eventually confirmed that WandaVision takes place after Avengers: Endgame, but just how far after wasn't clear. During the first three episodes of the show, there were no clues or Easter eggs that provided any clarity. With each episode set in a different sitcom decade and barely any mention of real MCU events, it was impossible to find out more. WandaVision was originally intended to be the second MCU Disney+ show and is confirmed to set up Doctor Strange in the Multiverse of Madness. While both of those facts might lead fans to believe it is set further into the Phase 4 MCU timeline, that is far from the truth.
The focus of Spider-Man: Far From Home in the timeline. This sets WandaVision in 2023.
Once WandaVision makes the time jump, it does begin to get a bit unclear how much time has ed. Monica is sucked into the energy bubble surrounding Westview and SWORD has an entire facility up and running less than 24 hours later. This is where Darcy enters the picture and begins monitoring the WandaVision broadcasts. Viewers don't know if the "episodes" play on a loop or how frequently a new one arrives. Previous WandaVision episodes suggest Scarlet Witch and Vision are at least somewhat aware that the decade jumps aren't natural and signify the ing of a single day instead of ten years.
It still appears WandaVision's events take place roughly three weeks after Avengers: Endgame's conclusion. That time frame is expected to remain, too, barring another time jump. This is fascinating to consider in the larger scheme of the MCU, as whatever happens in WandaVision doesn't appear to have any ramification on Spider-Man: Far From Home. It also signals that whatever happened to Scarlet Witch that resulted in WandaVision happens incredibly fast.