"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.