From: Saašha Metsärantala
Sent: Thursday, May 05, 2011 10:57 AM
Subject: Re: [DATETIME] Some comments about the BNF
>  Centuries
> > the intent is that the term "century"
> > be undefined, but that, still, '00'
> > means " The interval beginning with
> > year 0000 and ending with year 0099".
> According to the century note, such a period is noted in another way:
> "for 1900 to 1999 use 1900-01-01/P100Y."
> Consistently, I would expect that the
> > interval beginning with year 0000 and
> > ending with year 0099
> would be written
> which is longer, but much more obviously shows what it means.
I agree and my inclination, based on the ongoing discussion of century, is to purge ISO 8601 century support from the spec (remove feature 203). If you want to say "16th century" do it with a temporal expression.
> The following question will be:
> How should we write down a century when the source does not clarify
> exactly which years are meant? AFAIR, this was a use case. If we do not
> use a two digit number for that, we should formulate an alternative.
> One possibility would be to base it on our existing vocabulary, such as
> writing "the first century" as:
> This would meant the 100-year period begining approximately on the
> second of july of year 0000. I choose the second of july because it is
> at the middle of the year. One another (better) alternative would be to
> decide to write (for example):
> for the first (undefined) century.
I don't see that any of this is necessary. if you want to denote a specific 100 year period, one that has a knows start and end, do it as an interval, as you recommend above. If you want to refer to a century, then you are trying to refer to a notion that does not have a definition in our spec. Thus if you want to refer to 16th century we assume that you want to refer to the (relatively) vague notion of the 16th century and that you do not really intend to denote specifically when it began or ended, otherwise you would use the more-specific interval notation.