[redland-dev] Adding date/time datatypes to Rasqal

[Alberto Reggiori]

On Jul 14, 2004, at 10:30 PM, Dave Beckett wrote:
>
> The however... is a warning since datetimes are hard to get right,
> and especially hard to internationalise.  Simplified dates for
> computers such as the ISO formats are OK, but have lots of
> assumptions.  Requiring a timezone or not?  Allowing abbreviations of
> datetime or not?  Dates before the Gregorian year period? And so on.

yes I think most people assume/use UTC timezone and Gregorian calendar

> I'm not sure how much supporting C code for dates would be needed.
> Is converting it all to Unix dates sufficient?
>
> Of course, it is often something people ask for in query languages!

perhaps for inspiration here see what XQuery people have already defined

http://www.w3.org/TR/xquery-operators/#durations-dates-times

even though that list is too long to be easily implemented and made 
portable - but covering most of the general case

something simpler would be needed every day - not sure how other 
XML/RDBMS query languages / databases deal with dates though...

Alberto