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I'm sure someone will point it out, but GPS doesn't use leap seconds.

"Adding leap seconds is a waste of time" I see what you did there. And agree!

GPS is indeed happily unaware of leap seconds, it started counting seconds on January 6th, 1980 (UTC) {1 week is 604800s, weeks count 0..1023, there already was one rollover}.

http://imgur.com/a/uq6D0

A few minutes ago, when the screenshot was taken, this was second #501074 in week #1928.

As a courtesy to users, GPS transmits the current number of leap-seconds inserted in UTC (currently: 17) and the fact that a leap-second will be inserted the next occasion (end of this year: "LEAP PENDING!"). That's of course very helpful when you are using GPS disciplined clocks for timekeeping.

Interesting. I didn't know that. I think half of the point remains (what sounds like a small error can be critical) but I guess GPS isn't a great example, then, as safety critical systems tend to be smarter by design anyway.

The safety critical systems don't reset their clocks because safety critical systems maintain independence in order to maintain safety. Safety critical systems are a place where the abstraction of a Terran Year as a cosmological constant breaks down.

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