F-ckin Leap Seconds, how do they work?

Saku Ytti saku at ytti.fi
Tue Jul 3 17:59:05 UTC 2012

On (2012-07-03 10:11 -0700), Owen DeLong wrote:

> Trading one known set of bugs for a (probably) larger set of unknown bugs is not my definition of progress. Cost without progress is harmful and should be avoided.

Leap bugs are NOT known. Most people have no idea unixtime is not
monotonically increasing.
I had no idea myself until sunday, I had assumed we really go 59 -> 60 ->
00, but we go 59 -> 59 -> 00. So 59.1 can happen before or after 59.2.
To me this is fundamentally and inherently broken.

It's quite hard to find code which stores timestamp and then compares it in
future to timestamp which assumes time can travel backwards.
Most bugs are just things that should last 5s last 6s or 4s, but certainly
the bugs exist and developers were not aware that they exist.


More information about the NANOG mailing list