HTTP date format: RFC 850 or RFC 1036

Jim Davis (
Wed, 15 Dec 1993 10:22:32 -0500

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are to expressed in RFC 850 format, but RFC 850 has been
replaced by RFC 1036.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.