Re: Leap seconds: not a one-off unique event
There hadn't been one since 2009, which is longer than some of those big-name websites have been running on their current infrastructure.
I support a major industrial / scientific application and have been shitting myself for the last couple of weeks, when I found out accidentally about the leap second. I really should read those NANUs more often :-P
It also hit a major GPS vendor in a similar way as us: by the time they found there was a problem in their firmware, there was not enough time to fix it and push out the patches, so they had to email users with work-around instructions instead. Our problem was slightly different in that we didn't realise about the leap second until two weeks ago (they are published at least six months in advance), so we didn't have time to test--in the end, none of our users have reported anything amiss that I'm aware of, so all's well.
The point here is that, while not unique, it's infrequent enough that I lot of us don't give it the attention it deserves, particularly since high-precision timing has a lot more users nowadays than it had only a few years ago.
Be interesting to see what will happen when/if the first negative leap second is introduced.