[LEAPSECS] Greetings from an intercalary second

[Steve Summit]

I wrote:
> Some readers may be interested in the Date: line on this message.

I should have said: readers who are able to view the raw Date:
line "on the wire".  Any mail software which parses and
redisplays the date (including that which archives this mailing
list at pairlist6.pair.net) is likely to "normalize" it to 19:00.
But on the wire it was:

	Date: Sat, 31 Dec 2016 18:59:60 -0500

(Some people are saying to themselves, "And this just proves how
many different subproblems there are to solve if you want to
handle leap seconds properly everywhere", and they're right, of
course.)