On Tue, 28 Jan 2003, Peter J. Acklam wrote:
> [EMAIL PROTECTED] (Rick Measham) wrote:
>
> > There are two time periods that do not change: Years (time the
> > earth takes to travel around the sun) and Days (time the earth
> > take to spin one complete revolution). I'd suggest that these
> > the the two values that DateTime keeps internally. The 'year'
> > would be an integer delta from some Epoch (BC/1970) and the
> > 'day' would be a float representing how many days since the
> > start of the year value.
>
> Different calendars have very different ideas about what is a
> year, but pretty much every calendar has the notion of a day, so
> I'd go for using just the day and time of day.
>
> An example:
>
> Store the date as an array of two integers [N1, N2], where N1 is
> the days since some fixed date and N2 is the time of day. Then,
> even if both N1 and N2 must be in the interval [-2^31, 2^31-1] (to
> avoid overflow), you can let N2 be the nanoseconds, and thus one
> can represent any point in time within more than +/-5 million
> years with nanosecond precision using integers only!
Yes, that's how we're doing it, and is how we have been doing it for a
long long time. It's the format that I recommended in an
earlier note (Julian date, plus another number for time) and which we
subsequently implemented in Date::ICal.
--
Rich Bowen - [EMAIL PROTECTED]
... and another brother out of his mind, and another brother out at New
York (not the same, though it might appear so)
Somebody's Luggage (Charles Dickens)
