What is a Leap Second?

From Wikipedia:

"A leap second is a one-second adjustment that is occasionally applied to Coordinated Universal Time (UTC) in order to keep its time of day close to the mean solar time (UT1)."

There is a new leap second announced to happen 31st December 2016. See Bulletin C 52 from IERS (International Earth Rotation and Reference Systems Service). This means that the difference between UTC and TAI (Temps Atomique International) will be 37 seconds on the 1st of January 2017.

However, as leap seconds are not announced more than a few months in advance, the user have to schedule them as they become known. This is done with a few simple commands and there is no need to update to a new FW (Firmwire) version.

How does a Leap Second impact PTP devices?

PTP time is not affected by leap seconds and it’s only if you care about UTC time that you have to do anything about it.  An example is the case when you have an NMEA TOD input connected to your PTP master device or when you use NMEA TOD output.

All Qulsar units (M64, M68) running FW v2.8 or later are prepared for any upcoming leap second.

All Qulsar units running FW v2.8 or later have a file in the system directory called leapsec.ini. This file contains all historic leap seconds until the release date of the FW.

If you’re using a time source connected to your Qulsar device which provides UTC time (e.g. a GPS receiver), make sure that the time source is also prepared to handle the leap second.

To know more about leap second watch this video (110 MB, webm format):

Contact Qulsar if you are not able to watch this video


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