Hello

[edit]I checked the feed and this posting is present if I load the feed from this link (a minute after it's generation). It is not present at this time in firefox's built in reader! Maybe this is a caching problem?[/edit]

It showed up in my SeaMonkey 2.38 (like FF 41) with local time 15:46 (=the server’s and my location’s = CEST = UTC+2). In the source:
Received: by localhost; Mon, 12 Oct 2015 23:55:05 +0200
Date: Mon, 12 Oct 2015 13:46:04 +0000

[edit]
This one at local time 00:02:
Received: by localhost; Tue, 13 Oct 2015 00:04:09 +0200
Date: Mon, 12 Oct 2015 22:02:14 +0000
No problem.
[/edit]

In my case it was the necessity to reload the feed in firefox's builtin reader. The forum (this installation) itself serves the actual content in the feed at any request. So it does, when I loaded it over the direct link.

Let's state: We don't know the server and the client configuration of the thread opener.

Tschö, Auge