[LEAPSECS] A standard for leap second smearing

[Stephen Colebourne]

Leap second smearing is a way of taking UTC (with leap seconds) and
mapping it to a view of time that always has 86400 subdivisions per
day.

Tony Finch summarized five known approaches, which are all linear:

Amazon    -12h +12h
Bloomberg -0   +2ks
Google    -10h +10h
QTnet -"about 2 hours" +0
UTC-SLS   -1ks +0

The goal of this thread is to see if consensus could be found for one
approach of smearing.

The decisions would appear to be:

1) Linear or Other?
All current known smears are linear. Google previously had a different
approach, but changed to linear. Are there any major arguments against
linear? It would seem to be easier to specify and code that way.

2) When to smear?
Some smear up to midnight, some smear after midnight, some smear both
sides. What are the arguments for/against each?

3) Speed of smearing?
The existing approaches have two broad groups - fast (under an hour -
Bloomberg/UTC-SLS) and slow (20 hours or more - Google/Amazon) with
QTnet an outlier towards the fast end. What are the arguments
for/against fast/slow? Would there be a case for two agreed standards,
one fast and one slow?

4) Anything else?


While there are those on this list that dislike both leap seconds and
others that dislike smearing, I'd ask that this thread stick to
positive steps, to try and round out the arguments that would need to
be decided for a smearing standard to be agreed.

Stephen