HTTP date format: RFC 850 or RFC 1036

Jim Davis <>
Date: Wed, 15 Dec 1993 10:22:32 -0500
From: Jim Davis <>
Message-id: <>
Subject: HTTP date format: RFC 850 or RFC 1036
As has been pointed out, the HTTP draft specifies that dates
are to expressed in RFC 850 format, but RFC 850 has been
replaced by RFC 1036.

I wish to point out that RFC 1036 has a different format for dates
than RFC 850. Although neither RFC says so explicitly, the differences
seems to be that RFC 1036 uses a space to separate day, month, and year,
where 850 uses a dash; and 1036 uses three-letter forms of the day

Example of 850:        Weekday, DD-Mon-YY HH:MM:SS TIMEZONE
Example of 1036:       Wdy, DD Mon YY HH:MM:SS TIMEZONE

By the way, I can't resist pointing out that neither RFC provides an
explicit syntax for dates, other than to say that it must be
"acceptable both in RFC-822 and to the getdate(3) routine that is
provided with the Usenet software."  This is in keeping with the Unix
practise of defining "standards" by saying "it's whatever the
such-and-such routine accepts".  I don't see so much as a man page for
the getdate(3) routine, so who knows that the syntax really is.
Judging from the most recent usenet message I have seen, the dayname
(and comma and space) are optional.

Anyway, we need to make a clear decision which RFC to follow, since
there are incompatible differences.

Does anyone implement Date (or Last-Modified) response headers yet?
I do, and for now I am going with the new RFC.