Re: ADA.CALENDAR and midnight

["Nick Roberts" <nick.roberts@acm.org>]

On Thu, 05 Aug 2004 20:00:52 +1000, Brian May <bam@snoopy.apana.org.au>  
wrote:

> According to documentation I have:
>
> subtype DAY_DURATION is DURATION range 0.0 .. 86_400.0;
>
> How is midnight meant to be represented?
>
> I would have assumed it would be 0.0, the next day, but preliminary
> tests, unless I am confused, seem to show it is represented as
> 86_400.0 (using gnat compiler for Windows)? The following quote from
> the documentation would seem to imply I am correct; "SECONDS
> indicating the number of seconds past midnight", but I am getting
> behaviour which suggests otherwise.
>
> Why are both 0.0 and 86_400.0 defined to be legal values?  Aren't
> they both the same thing (but one day apart)?

RM95 (TC1) 9.6 (25) states:

    If Time_Of is called with a seconds value of 86_400.0, the value
    returned is equal to the value of Time_Of for the next day with a
    seconds value of 0.0. The value returned by the function Seconds or
    through the Seconds parameter of the procedure Split is always less
    than 86_400.0.

So I would say that an implementation which returns 86_400.0 is
faulty.

-- 
Nick Roberts