AniList doesn't count watched/completed animes if start_date
isn't set. See forum thread.
This website corrects invalid dates.
It takes in a MyAnimeList XML file, then sets invalid dates to valid dates for all completed
animes.
For example, if start_date is invalid & finish_date is valid, then start_date =
finish_date, and vice versa.
This only works for Anime. Not Manga.
If there's enough interest for it, I'll add Manga functionality, if not, then someone else can
fork
my
code and make their own.