[LEAPSECS] Greetings from an intercalary second

[Steve Summit]

Some readers may be interested in the Date: line on this message.
It is not faked: it was added by a lightly-modified sendmail
program running under a Linux kernel keeping true UTC, with the
timestamp fetched via clock_gettime(CLOCK_UTC) and formatted
using a timespec-aware version of localtime().

I don't claim that the code behind this demonstration solves every
leapsecond-related difficulty (far from it!), but it's a start.