Re: roundoff problem in time datatype

Tom Lane wrote:
> Dennis Bjorklund <db(at)zigo(dot)dhs(dot)org> writes:
>
>>Do the sql standard say anything on the matter?
>
>
> It doesn't seem very helpful. AFAICS, we should interpret storing
> '23:59:59.99' into a TIME(0) field as a cast from TIME(2) to TIME(0),
> and the spec defines that as
>
> 15) If TD is the datetime data type TIME WITHOUT TIME ZONE, then let
> TSP be the <time precision> of TD.
>
> b) If SD is TIME WITHOUT TIME ZONE, then TV is SV, with
> implementation-defined rounding or truncation if necessary.
>
> So it's "implementation-defined" what we do.

IMHO Since 23:59:59.99 probably means "the last milliseconds of this
day, as far as precision allows to express it", this should be truncated
to 23:59:59, not rounded to 24:00:00. Until the last microsecond has
elapsed, it's not 24 hours (you wouldn't round "happy new year" at
23:59:30 from a clock with minutes only either)

Regards,
Andreas