[ntp:hackers] smearing the leap second

Mike S mikes at flatsurface.com
Thu Jul 9 17:02:17 UTC 2015

NTP shouldn't be involved in "smearing" time, at all. The only reason 
for smeared time is because of systems (e.g. POSIX) which don't properly 
support leap seconds. Any smearing should be done by the OS, not NTP, 
which should strictly follow UTC. To do otherwise is to deliberately 
break NTP.

Even then, NTP and parts of RFC 5905 are fundamentally flawed even in 
that regard - it's supposed to count leap seconds with a "monotonically 
increasing" timescale, but in practice has the same flaw as POSIX. It's 
simply not a well designed (or documented for that matter, search for 
"leap" in the RFC) protocol.

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