Time Libraries Rough Draft
p.turner at computer.org
Fri Feb 11 17:13:47 EST 2005
On 2005 February 11 Friday 12:57, Aaron Denney wrote:
> I think ideally we would have two interfaces, one of which does its best
> guess at POSIX UTC and one which does its best guess at TAI, because a
> best guess at UTC converted to TAI (or vice-versa) has more paths for
> this inaccuracy to creep in.
Agreed regarding two interfaces. However, the proposed getCurrentTime makes
careful allowance for being the best guess at TRUE UTC. I wrote:
> > 2. In a UTCTime, is the DiffTime limited to 86400 or 86401 or unlimited?
Ashley Yakeley replied:
> The maximum value is 86401*10^12-1. The minimum value is 0.
So during a leap second, the DiffTime field returned by getCurrentTime should
be between 86,400,000,000,000,000 and 86,400,999,999,999,999. That is, it
should indicate an hour, minute, second of 23:59:60. With current OSes this
will not happen because they fudge the leap second. When the improvements to
NTP are available, true UTC can be supported by getCurrentTime.
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