Gmail – How to set locale so language reply headers are in de-DE

gmaillocalization

How can I set up Gmail and set the language such that replies to emails set the correct language of the reply headers to that set locale/language?

So, instead of English I want German to show up:

-------- Original Message --------
From: sam@email.com
Sent: Thursday, December 16, 2010 9:33 AM
To: bob@email.com
Subject: Good morning!

…to this (in the case of German):

-----Ursprüngliche Nachricht-----
Von: sam@email.com
Gesendet: Donnerstag, 16. Dezember 2010 09:33
An: bob@email.com
Betreff: Good morning!

Best Answer

As of 2017-01-23, Settings > General > Language > Gmail display language seems to work. However, I tested it by forwarding, not by replying, as you needed. Reply formatting seems to be now very bare, not the standard header. Thanks @ale for hint