Date field value incorrect

[maikusch]

I think i found an issue on date fields

My form has a field of t type date.
this renders an input with type="date".

default behaviour is, that the 'value' is always in format Y-m-d.
so, if i type a german date like 05.04.1984 the value is set to 1984-04-05.

If i debug the ext:form request the value is correct set to 1984-04-05.
but, the brevo finisher, ignores this and the value is like typed in 05.04.1984.

the brevo API only accepts dates in the format Y-m-d. so the API is always responding with a 400 "invalid date format" message.