package calendar accuracy

[contr47@nosc-tecr.UUCP ("CONTR47")]

What are your package calendar accuracy requirements
with respect to the following:
1. Once/year 23 hour day
2. Once/ year 25 hour day
3. Once/ 4 years 29 day February
4. Addition of 1 second approx once per year to correct for
   slowing of earth rotational velocity.
(note: you get about 3 months notice of this addition)
  The ARM says that "+" and "-" have "the conventional
meaning". What is the convention in these cases?
If I perform a +/- on the day before/after one
of the above 4 events what is "the convention"?
If I ask package calendar for the time is it required
to always give the correct answer? The ARM seems silent
on time accuracy so what are your requirements?
(I heard on radio news this fall that Amtrak has it's
trains stop for one hour to maintain schedule
when clocks are set back. I don't know if this is true
or not and they didn't say how they handle the
setting ahead of the clocks in the spring.) 
regards, sam harbaugh
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