Date: Wed, 18 Jun 1997 18:57:37 +0000 (GMT) From: Misha Wolf <email@example.com> Subject: Date/time on the Internet In-Reply-To: To: meta2 <firstname.lastname@example.org>, www-html <email@example.com> Cc: Chris Newman <firstname.lastname@example.org> Message-Id: <2337571818061997/A29474/REDMS1/11B694B92400*@MHS> Increasing numbers of Internet-related protocols and standards need to reference dates/times in a standard manner. The base standard mostly used for this purpose is [ISO 8601]. This agreement on one base standard is a Good Thing. A note for folks working with dates where YYYY < 0000 or YYYY > 9999: I know ISO 8601 isn't right for you. You'll need to use another standard which fits your requirement. Sorry. ISO 8610 is a *very* permissive standard and so each Internet-related protocol/standard is making up its own profile of ISO 8601. That is a Bad Thing. Some of these are conformant profiles; others are not. And that's a Very Bad Thing. Some of the profiles are more restrictive; others are less so. An example of a non-conformant profile is that used by PICS 1.1 [REC-PICS-labels-961031]; see the extract below. This profile is non-conformant in that it separates the YYYY and MM and DD portions using the character "." instead of "-". The PICS profile is also surprisingly restrictive, in that it does not permit seconds to be included. An example of a conformant profile is that used by [draft-newman-datetime-01.txt]. This profile is also rather restrictive for some Internet-related protocols and standards, in that it mandates the use of hours, minutes and seconds. Some users may wish to specify only a date when creating metadata. Chris has agreed to make the time portion optional in his next draft. I would suggest we need a single profile which is: - conformant, - widely adopted, - easy to understand, - not too permissive, - not too restrictive, - electronically available. We also need to persuade the people specifying forthcoming standards such as PICS-NG, Cougar, etc, to use this profile. So, how do we proceed? Chris Newman's Internet Draft has two further disadvantages: (i) it's an Internet Draft (rather than an RFC) and (ii) it is made rather large and intimidating by catering for dates/times in the future and the associated mish-mash (did I spell that right?) of time zones. One possibility would be for Chris, who is currently busy on other important stuff, to find the time to split his Internet Draft into two: (i) a quickie covering just a profile of ISO 8601 and (ii) another, covering the more complex stuff. Another possibility would be for someone else to do the job (I'm not volunteering). Comments? A note on distribution: I have not found a single suitable forum for this topic, so I suggest it be discussed on the open lists (email@example.com) and (firstname.lastname@example.org) and request that you send your responses to those two lists. I'll forward this initial message to a few other relevant lists, mostly closed ones, to give people on those lists notice of this thread. REFERENCES: [ISO 8601] "Data elements and interchange formats -- Information interchange -- Representation of dates and times", ISO 8601:1988(E), International Organization for Standardization, June, 1988. [REC-PICS-labels-961031] "PICS Label Distribution Label Syntax and Communication Protocols", Version 1.1, W3C Recommendation 31-October-96. [draft-newman-datetime-01.txt] "Date and Time on the Internet", Chris Newman, Internet Draft, January 1997. An extract from [REC-PICS-labels-961031] follows: quoted-ISO-date :: '"'YYYY'.'MM'.'DD'T'hh':'mmStz'"' based on the ISO 8601:1988 date and time standard, restricted to the specific form described here: YYYY :: four-digit year MM :: two-digit month (01=January, etc.) DD :: two-digit day of month (01 through 31) hh :: two digits of hour (00 through 23) (am/pm NOT allowed) mm :: two digits of minute (00 through 60) S :: sign of time zone offset from UTC ('+' or '-') tz :: four digit amount of offset from UTC (e.g., 1512 means 15 hours and 12 minutes) For example, "1994.11.05T08:15-0500" is a valid quoted-ISO-date denoting November 5, 1994, 8:15 am, US Eastern Standard Time Note: The ISO standard allows considerably greater flexibility than that described here. PICS requires precisely the syntax described here -- neither the time nor the time zone may be omitted, none of the alternate formats are permitted, and the punctuation must be as specified here. ----------------------------------------------------------------------- Misha Wolf Email: email@example.com 85 Fleet Street Standards Manager Voice: +44 171 542 6722 London EC4P 4AJ Reuters Limited Fax : +44 171 542 8314 UK ------------------------------------------------------------------------ Any views expressed in this message are those of the individual sender, except where the sender specifically states them to be the views of Reuters Ltd.