Time Libraries Rough Draft

Scott Turner 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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