Seasons 21-25

Holidays of Future Passed (Season 23, Episode 9)

"Holidays of Future Past" is the most recent flash-forward episode of The Simpsons. It aired in 2011, and is supposed to represent 30 years into the future. There are several examples of futuristic technology in the episode, including a teleportation machine that transports Bart's children into his apartment, and a "Medbot" delivering Maggie's baby.

An interesting representation of the internet is portrayed in this episodes, with users literally being drawn into a different "world", unable to communicate with people who are not online. In the episode, Lisa feels a disconnect from her daughter, who is always online and does not communicate with her. Later in the episode, this leads to Lisa developing a new found appreciation for all that Marge put up with raising them, creating a sort of timeless feel to Lisa's situation, even though it is heavily based in futuristic technology

Days of Future Future (Season 25, Episode 18)

This episode is a sequel to "Holidays of Future Passed". In the episode, Homer has cloned himself hundreds of times, but because of this he is very reckless and each clone version of him dies. However, Professor Frink "downloaded Homer's personality" onto a USB, and he lives on in a computer for most of the episode. This and "Holidays of Future Passed" are the only two flash-forward episodes that are not told through some character's vision of the future, making continuity between them and other flash-forward episodes unimportant. In this episode, like Holidays of Future Passed, Lisa is married to Milhouse, and Bart is divorced from his ex-wife, Jenda. This episode discusses more biological advancements and changes, rather than discussing the internet and social networking. Besides the Homer clones, Jenda dates an alien, and Milhouse becomes a zombie. 

One continuity error between episodes are Bart's children, who do not appear to have aged in the five years that are supposed to have been between them. Lisa's daughter is not seen at all, but she was old enough in the previous episode that it can be assumed that she has moved out.