Break-Age

Every cinema or direct to video anime film that came out in 1999.

1998: https://myanimelist.net/stacks/34766
2000: https://myanimelist.net/stacks/34774

Disclaimer: There are a few hentai movies, that could be counted as well:
- Hokenshitsu de Aimashou (1999)
- Misato-chan no Yume Nikki (1999)

These are just some which I've seen and plan to watch. Includes movies and OVAs.
This list might keep getting updated.

Part 2 here : https://myanimelist.net/stacks/37380

Anime that, at the time of the release, was set at least a year into the future but with a date that has already come to pass. Also includes anime with plot-important events set in a future that has already passed, even if the anime's main setting still remains in the future.

Ran out of space on my first list https://myanimelist.net/stacks/30015 (2011-present), be sure to check that one out too!

This list contains works set in 2010 or before.

Sources:
- Wikipedia https://en.wikipedia.org/wiki/List_of_stories_set_in_a_future_now_in_the_past
- TVTropes https://tvtropes.org/pmwiki/pmwiki.php/Main/NextSundayAD , https://tvtropes.org/pmwiki/pmwiki.php/Main/TwentyMinutesIntoTheFuture
- AniList forum thread https://anilist.co/forum/thread/65789 (used only in the case of no other sources being found)
- other sources include anime wikis, anime synopsis (on MAL or other source if mentioned) and the anime itself if a date is stated during the runtime

I'm open to any corrections and additions!

Manga, LNs and other literature set in a future now in the past: https://myanimelist.net/stacks/30071

Group of friends watching some weird forgotten stuff

(updated daily)