It is known that “Earth616” is trying to keep track of when events in the MCU timeline ocurs. Likewise it is for WandaVision, which is still under discussion amongst some fans. So far, there are only theories that the events itself initializes shortly, up to year, after the events of Avengers: Endgame. So according to the timeline of MCU, the initial events probably lands in 2023-2024 MT (McuTime).
According to Collider, WandaVision will be paying homage to virtually every decade of TV sitcoms, but what this really means to the “occuring time” is still unknown.