"uncertain and unspecified"  is logically inconsistent because if a date is uncertain then by definition it is “specified”.


From the ISO dis, the definition:



date whose source is considered dubious


If a date is uncertain then by definition it has a source.   If it has a source, then it must be “specified”.




From: Discussion of the Developing Date/Time Standards [mailto:[log in to unmask]] On Behalf Of David Newbury
Sent: Wednesday, March 08, 2017 2:55 PM
To: [log in to unmask]
Subject: [DATETIME] Uncertain, unspecified dates


I'm trying to implement a system using EDTF, and I'm trying to record an event which:


1. Took place with day precision. (It is a discrete event, and my system does not record with more than day precision)

2. Is uncertain (I have a date, but I am unsure if it is accurate)

3. Is unspecified.  (I know the year it took place in, but I cannot yet determine the month or day).


It seems logical that this would be recorded as  1990-uu-uu?, but that does not appear to be a valid EDTF date.


Is there a reason that "uncertain" and "unspecified" cannot be used together?  They seem to be orthogonal concerns.


- David Newbury
p. (773) 547-2272
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