The leap seconds are coming, the leap seconds are coming.
Oh, great–first the government mucks with DST, and now leap seconds are back for the first time in 7 years. I was starting to think that we were done with them for good.
My timezone is going to have an extra second added at 3:59:60 PM on
December 31st, 2005. Fun; I wonder how many of the devices that I deal
with will do the right thing with the extra second. Odds are most of
them will just end up an extra second off. I assume that NTP
has a way of dealing with this, although it might just be outside of
the protocol’s scope–leap seconds really just change the
seconds-since-some-epoch to human-visible-date mapping. (Update: it’s complicated)
Since leap seconds aren’t new, and I don’t really care about
sub-second timing precision on any of my devices, I doubt I’ll even
notice the change, although undoubtedly there are devices on the market
that will have problems; I wouldn’t be surprised if there’s a cheap GPS
receiver somewhere with leap seconds issues.
This reminds me of two of the pedantic sysadmin interview questions
that I’ve never really had the guts to ask a real candidate–“exactly
how many hours are in a day?” and “how many seconds are there in a
minute?” Strictly speaking, the answers are “23, 24, or 25, depending
on DST transitions” and “59, 60, or 61, depending on leap seconds.” The
23/24/25 thing actually bites new sysadmins–never schedule something
that needs to happen exactly once per week to happen between 2:00 and
3:00 local time on a Sunday morning, because once per year it won’t
happen at all, and another time it’ll happen twice. [*scottstuff*]