ashley at semantic.org
Thu Jan 27 03:09:17 EST 2005
<3429668D0E777A499EE74A7952C382D1030DE110 at EUR-MSG-01.europe.corp.microso
"Simon Marlow" <simonmar at microsoft.com> wrote:
> I like the idea of having a single notion of absolute time, which is
> independent of TAI or UTC time. You can do arithmetic on absolute time
> (add/subtract absolute units of time, find absolute time differences),
> and convert to/from TAI and UTC.
> My library happens to keep absolute time as TAI seconds since the epoch,
> but it doesn't have to. A representation using (days,ticks) sounds like
> it might be hard to do arithmetic on, though.
I think your ClockTime is a sensible way to represent absolute time for
TAI. But we also need something that represents (for instance)
"2008-08-03 11:00:00 UTC" even though we don't know what precise TAI
time that will be. For this I would consider using a (days,ticks) pair:
it allows you to do arithmetic such as "5 UTC days later" and end up
with the expected answer even when there are intervening leap seconds.
Ashley Yakeley, Seattle WA
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