No "Date:" line in digest header

[Tkdubs]

I am running Mailman-2.1.5.

Mailman fails to insert the "Date:" line in the header,
which can cause problems for MTA's which do not inject
a "Date:" line (such as qmail).

Each individual message within the digest has a date
line in its header, but the digest itself is missing
the Date line. This causes mail readers like
Thunderbird to label the message as being sent on Dec.
31, 1969.

Most MTA's and MUA's inject a Date line, but I'm using
Qmail as an MTA -- which doesn't inject one. It is
the job of the MUA (Mailman in this case) to create the
Date: line according to RFC-2822.

This was fixed for non-digested messages delivered to
lists in 2.1-beta-1 of Mailman according to the NEWS
file, but has not yet been addressed for delivery of
digests.

[http://sourceforge.net/tracker/index.php?func=detail&aid=1023942&group_id=103&atid=100103]

[Janschlosser (janschlosser)]

This one is fixed by patch 1116952, although the patch file
didn't work without manual rewriting to the ToDigest.py
source file