Changing quoting headers?

[Hermann]

Hi,
When I reply to a message, the quoting starts with:
[full name] <mailaddress> writes:
How can I change this, so that it looks like this:
On [dd,mm,yy] [full name) <mailaddress> wrote:
Note: I want to use the German style of date, see my example.
I couldn't find something in the manual that clarifies this.
And, in addition: What to write if I prefer the discordian instead of
the gregorian calendar?
Any tips and hints?
Hermann

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