[ntp:questions] Trouble Simulating Leap Seconds

Jim Witschey jim.witschey at datastax.com
Wed Apr 1 20:20:57 UTC 2015

Hey all,

I'm trying to simulate a leap second on a cluster of Ubuntu AWS
instances via NTP, and I could use some help. I've set up a basic NTP
server with a leapfile as described here:


The server's warning for the upcoming leap second seems to propogate
to the clients, as I see `leap_armed` in the output for `ntpq -c rl`
before midnight, and `leap_event` afterwards. However, when I loop
`date -u` over the leap second, I don't see a leap second getting
inserted -- I expect 23:59:59 to last for 2 seconds, but it doesn't.
The time goes straight from 23:59:59 to 00:00:00 the next day.

In addition, I don't see any information about inserted leap seconds
in the logs when I search with `dmesg | grep leap` or `sudo grep leap

Am I missing something? I can provide more information on request.

Jim Witschey

More information about the questions mailing list