who are you directing this post to??
Comment is directed to family search. I couldn't find any other place to respond.
which Marianne of the tens of thousands in the database are you referring to?
and what calendar are you referrrin to?
are you referring to a record in FamilySearch Family Tree?
If so what is her record ID?
what is Marrianne's last name?
her parents names?
where was she born?
As Dennis says, nobody here (including any FamilySearch employees) would know the details of your Marianne. However, you do highlight an ongoing problem with the confusion caused by different sets of date formats being used. For example, nobody reading this would know whether her actual birthday was 9 May or 5 September!
I believe the message you received would be a "computer generated" one, so there has been no human error, as such. Hopefully, a FamilySearch employee reading your post (and these added comments) will realise a little work needs to be carried out before these messages / calendars are sent out, to avoid such mix-ups.
is Marianne deceased or living? If deceased - can you tell us what her last name is?