Hi Magnus,
Not sure how the bot got "1900" as value at .
I could find "19..", but that would be 20th century.
Topic on User talk:Magnus Manske
- https://www.wikidata.org/w/index.php?title=Q3270372&type=revision&diff=684933453&oldid=635611335
- https://www.wikidata.org/w/index.php?title=Q15944884&type=revision&diff=684991611&oldid=625863272
from the same day seem to have the same problem.
Just noticed that this is the same as Wikidata:Project_chat#Bad_birthdays.
Also, see Talk:Q23759736