Many interesting ideas have been written on this list! That is good!

> > If there are use cases, I would really like to include such precision
> Use cases, I think, are a plenty. I think I have over the course of this list presented quite a few....
OK! There are use cases! Fine! Let now try to formulate something useful 
and (preferably) not too ambiguous! Some good attempts have be achieved! 
Thanks for that! Here are some comments about them.

> Yester[day|week|month|year]
This grammar does not seem to be the one we have used in our BNF. To 
prevent misunderstandings, I would suggest to clarify which grammar is 
used in these productions. Is anything within square brackets required or 

> NNNN century (as in "19th century", "19 Jh." etc)
I would welcome a clarification about the semantics of "Jh."!

> [Last|Past] [NNN] Sec[onds]|Min[utes]|H[ours]|Day[s]|Week[s]|Month[s]|Year[s]|Decade[s]|Millennium [Ago|Past]
Is it OK with constructs such as

Past 0 Millennium Past


Last 1 Hours ago

and the questions such constructs would rise? Or do I misunderstand the 
grammar? Days, Decades (etc.) may be written as whole words in both 
singular or plural, whereas Hours, Minutes and Seconds may not, or maybe 
not? What applies here?

> "Yesterday" is date precision while "Past Day" is date/time precision.
This could be useful, maybe. But such a contruct is something I would call 
"error prone" because many people would probably misunderstand these 
subtleties, especially if we keep in mind the following quote from this 

> given the lack of widespread "precision consciousness" at this time.
That is VERY important, I think!

I consider it could be useful to include the concept of precision in EDTF. 
My opinion that this would require a specific syntactic construct is 
stronger than ever. My aim is not to "over-complicate" EDTF. Instead, I 
consider that there is a need to help EDTF users to avoid to use (and 
misunderstand) constructs implying semantics they are not aware of.

Such a precision specific syntactic construct would also be useful to fine 
tune a higher granularity. Issues written on this list contain the 
following ones:

> The problem is with 10s left of the decimal point.

> the generalized "x" syntax.

A precision specific syntactic construct would make it easier to achieve a 
higher granularity and, for example, to write a date with a "3 days 
precision" - even when two different months are involved - such as

1996-05-01 \G3D

(using the syntax I suggested earlier). But that is only one example ...