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You might want to look at the TEMPER dates that CDL has proposed. This isn't a standard, but I suppose it could become one. It is designed to handle ranges, approximate dates, etc. http://www.cdlib.org/inside/diglib/ark/temperspec.pdf kc Rebecca S. Guenther wrote: > ISO 8601 has limited ability to express a lot of types of dates, > especially some needed for cultural heritage objects, like those that are > questionable, approximate, etc. Perhaps we should come up with some PREMIS > conventions. I looked at this a few years ago in the context of some > Dublin Core work and could dig up my notes if needed on the limitations of > 8601. There has been little consensus on conventions for these kinds of > uncertain dates. So it may be prudent to establish some for PREMIS perhaps > based on what other efforts may be using. > > Rebecca > > On Fri, 16 Jun 2006, Matthew Beacom wrote: > > >> Hello, >> >> It may be that one simply can't use ISO 8601: 2004 this way. Using >> 9999 and 0000 to represent not "dates in the Gregorian calendar" but >> rather a quality of open-endedness with respect to an end date or a >> start date is logically outside of the domain of ISO 8601. Anything >> we do would be a kluge. >> >> 9999 may not be the best value to mean "forever" as it would also >> mean the year 9999. A bit far off to worry about, of course. And OOOO >> would mean 1 BCE (or be illegal) as there is no year 0 between the >> first year of the common era (1 CE) and the last year prior to the >> 1st year of the CE (1 BCE). >> >> I think, though, that 0000 is not needed since a way to represent the >> open-endedness of a start date is not needed. The rights related to >> the object can't pre-date the object itself. So One can simply use a >> practical (albeit) arbitrary start date such as the date of the >> creation of the digital object or, if necessary, the date of the >> original object for which the digital copy is a proxy. >> >> And then--for about 8000 years anyway--9999 may work perfectly well >> being used to mean endless. But, of course, that would be a >> non-standard use of 9999. >> >> Matthew Beacom >> >> p.s. below is the abstract for ISO 8601: 2004 from >> http://www.iso.org/iso/en/CatalogueDetailPage.CatalogueDetail?CSNUMBER=40874&ICS1=1&ICS2=140&ICS3=30 >> >> ISO 8601:2004 is applicable whenever representation of dates in the >> Gregorian calendar, times in the 24-hour timekeeping system, time >> intervals and recurring time intervals or of the formats of these >> representations are included in information interchange. It includes >> * calendar dates expressed in terms of calendar year, calendar >> month and calendar day of the month; >> * ordinal dates expressed in terms of calendar year and calendar >> day of the year; >> * week dates expressed in terms of calendar year, calendar week >> number and calendar day of the week; >> * local time based upon the 24-hour timekeeping system; >> * Coordinated Universal Time of day; >> * local time and the difference from Coordinated Universal Time; >> * combination of date and time of day; >> * time intervals; >> * recurring time intervals. >> ISO 8601:2004 does not cover dates and times where words are used in >> the representation and dates and times where characters are not used >> in the representation. >> >> ISO 8601:2004 does not assign any particular meaning or >> interpretation to any data element that uses representations in >> accordance with ISO 8601:2004. Such meaning will be determined by the >> context of the application. >> >> Matthew Beacom >> >> Metadata Librarian >> Yale University Library >> 130 Wall Street P.O. Box 208240 >> New Haven, CT 06520-8240 >> >> phone: (203) 432-4947 >> fax: (203) 432 7231 >> e-mail: [log in to unmask] >> >> > > > -- ----------------------------------- Karen Coyle / Digital Library Consultant [log in to unmask] http://www.kcoyle.net ph.: 510-540-7596 fx.: 510-848-3913 mo.: 510-435-8234 ------------------------------------