Precise Expansion Patterns (was: Re: [uf-discuss] Hcalendar in bbc.co.uk/programmes)

[Paul Wilkins]

On Dec 15, 2007 1:36 PM, Paul Wilkins <pmw57 at xtra.co.nz> wrote:
> On Dec 15, 2007 1:21 PM, Martin McEvoy <martin at weborganics.co.uk> wrote:
> > hmm are you sure? 3:23 is expressed as whole plus a decimal fraction
>
> That's if you use a comma or a fullstop. With the full colon it's
> interpreted as hours and minutes.
> [QUOTE]
> It is also acceptable to omit elements to reduce precision. [hh]:[mm],
> [hh][mm] and [hh] are all used.
>
> Decimal fractions may also be used with any of the three time
> elements. These are indicated by using the decimal point (either a
> comma (which is preferred ISO 31) or dot). A fraction may only refer
> to the most precise component of a time representation. To denote "14
> hours, 30 and one half minutes", do not include a seconds figure.
> Represent it as "14:30,5" or "1430,5".
> [/QUOTE]

The least that could be got away with is 00:03:23, at which point it
would be a toss up between that or PT3M23S

Both of the above formats are valid and should be accepted by parsers
as a part of the ISO 8601 time/date format.

Issues when people markup using the first example are that they are
tempted to leave out the hours part and put in 03:23 or even just
3:23, and are left puzzling about why it's interpreted as 3 hours 23
minutes.
Issues with the second format is that the abbr tag is in danger of
blowing up from excessive stretching of its semantic meaning.

-- 
Paul Wilkins