Draft for review: ISO 8601 date work on IS 29500

[Chris Rae]

Hi all - I think Jesper's last proposal ("When used in formulas specified in this specification, dates and times should be converted to serial date values") is a good halfway house that gets everyone what they're after. If nobody has any objections I'm going to modify our draft to use that wording.

Chris

-----Original Message-----
From: Jesper Lund Stocholm [mailto:jesper.stocholm at ciber.dk] 
Sent: 26 July 2010 23:45
To: Chris Rae; rjelliffe at allette.com.au; e-sc34-wg4 at ecma-international.org
Cc: Horton, Gareth
Subject: RE: Draft for review: ISO 8601 date work on IS 29500

Good morning, Chris


> -----Original Message-----
> From: Chris Rae [mailto:Chris.Rae at microsoft.com]
> Sent: Monday, July 26, 2010 10:55 PM
> To: Jesper Lund Stocholm; rjelliffe at allette.com.au; e-sc34-wg4 at ecma- 
> international.org
> Cc: Horton, Gareth
> Subject: RE: Draft for review: ISO 8601 date work on IS 29500
> 
> I just spoke to Gareth about this, to make sure I wasn't off on my own 
> here. We may be against the use of "may" in this instance.

-----------^^^------------------------^^^

*giggles* :o)


> I'd argue that it would be very hard to fully interoperate in formulas 
> with any other spreadsheet application without using serial values, so 
> we'd be steering people towards the wrong course by using "may" here.
> Unless you know in advance what sort of date formulas you're going to 
> see, you really ought to implement serial values.

I completely agree that you want to implement serial dates if you are creating a (full) Spreadsheet application with the intention of interoperating with other users using other programs than yours.

But what if you are not trying to implement a spreadsheet application but simply needed to process the data in a spreadsheet? What if you were not implementing a presentation application but merely a "slide sorter"?
We want the text to be usable for both simple and complex usages.

In my opinion the current text-fragment we are talking about is aimed at people/companies creating huge application suites like Lotus Symphony, Microsoft Office etc. It is clear that these folks need to implement serial dates. 

But the specification needs also to be targeted at other usages with much, much more limited scope. In my example it would be a huge overhead to implement serial dates simply to subtract two days from a date (with the specified epoc implemented as well, of course). You'd simply use the tool of your choice and x => x.Subtract(2) or whatever the syntax is of your language.

(and I realize that there will probably be some internal conversion of dates in the tool of choice, but for us (and OOXML) this is irrelevant.)

> Could we say "When used in formulas, dates and times behave as though 
> they were serial date values"? It seems like that would steer people 
> towards using serial values, but not mandate it for conformance.

I think we need an ISO modal verb here. How about using "should"?

"When used in formulas specified in this specification, dates and times should be converted to serial date values"

Doesn't that strike a reasonable compromise between steering people in the direction of implementing serial dates - while still allowing them to make a conscious choice not to - if they don't have to in their specific usage?

Murata-san, do you have some specific wording in mind in re: to Dennis and suggestion to how to incorporate it into the text?


Med venlig hilsen / Best regards

Jesper Lund Stocholm

CIBER Danmark A/S
Mobil: +45 3094 5570
Email: jesper.stocholm at ciber.dk