[boost] Re: boost::date_time: ISO compliant IO for periods/durations?

From: Daniel Krügler (dsp_at_[hidden])
Date: 2004-05-11 10:45:43

Jeff Garland schrieb:
> On Tue, 11 May 2004 14:43:54 +0200, Daniel Krügler wrote
> 
>>Hello boosters,
>>
>>I would like to know whether there already exist ISO 8086
> 
> 
> I assume you mean ISO 8601...

HeHe, of course. 8086 was the other magic number any DOS historian
is aware of....

> 
> 
>>conforming extractors/inserters for the duration/period
>>classes? Specifically I am looking for io/string functions which
>>can handle "Periods of Time, no Specific Start or End", which
>>begin with a 'P' following a list of periods, e.g.
>>
>>"P18Y9M4DT11H9M8S" (18 years, 9 months, 4 days, 11 hours,
>>9 minutes and 8 seconds)
> 
> 
> I'm afraid the library doesn't currently offer an extraction of this sort of
> duration.  The primary reason is that I (and others) have had difficulty
> dealing with the imprecise nature of a time duration that includes years and
> months.  The problem is, what is the length of a duration such as '3 months'?
>  The answer is, it depends on which day you want to measure it from and what
> rules you want to apply.  So for representing durations you currently only
> have days, hours, minutes, and seconds.
> 
> So the question goes back to you -- what are you going to do with these
> durations? If you can answer that, it shouldn't be difficult to write a
> parsing function...
> 
> Jeff
> 

OK, I understand the nature of the problem here. And probably it 
wouldn't help, if ISO 8601 would define a month in this context,
would it? Regrettably I have no access to the full 8601 spec, but does
anyone have?
Lets assume, that ISO 8601 would provide a resolution, would it make 
sense to make such an iso_... function available (Because it would 
depend on a special calendar definition)?

Thanks for your reply,

Daniel