On Fri, 13 May 2011 20:24:08 +0200, [UTF-8?]SaaÅ¡ha Metsärantala wrote
> > Volatile / dynamic dates
> I assume we mean "deictic dates" and, in this case, I would suggest to use 

By "volatile" was indeed, generally, deictic meant, viz. date expressions 
whose meaning is only defined by context from the perspective of speaker 
resp. listener. These are of significant utility in query languages to 
standardize the common concepts of "today", "now", "14 days ago", "tomorrow" 
and intervals such as "past 14 days", "last 2 weeks", "this year" etc.

These I need. I currently have, lacking a standard, my own vocabulary. While 
a date interval such as "past 14 days" can be calculated it is not always 
reasonable. A search response, for example, that could return a facet 
with "past 14 days" is much easier to implement and more efficient to use. 
Queries with date expressions using something like "today" are reusable--- 
for example, "give me news stories about the Giro d'Italia today" for 
current stories--- while their caculated instances are not (refer only to 
the day that was caculated).

In our standard, however, we have a number of deictic concepts such 
as "seasons" (these don't just differ between Northern and Southern 
Hemisphere but also vary between astronomical and meteorological as among 
cultures) that are NOT volatile. These are really not unlike named events, 
resp. intervals. The date or interval meant by these expressions do not 
change according to when they are uterred. 

We have also dicussed in this list a number of "dynamic" or calculated 
dates. Common calculated dates were, for example,  U.S. election day (first 
Tues in November) and a number of U.S. bank hollidays such as Labour Day, 
Presidents day etc. 

> the word "deictic" for clarity. Otherwise, the reader may wonder what kind 
> of "nearly-deicitc" but "non-diectic" thing we mean here.


Edward C. Zimmermann, NONMONOTONIC LAB
Basis Systeme netzwerk, Munich Ges. des buergerl. Rechts
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