It’s that special time when the ER&RSS decides we need an extra leap second. I’ve not looked into the details, but instead of the clocks going from 23:59:59 to 00:00:00 the night of June 30, 2015, there will be an extra second added: 23:59:60. Of course computer clocks aren’t going to appreciate a second called “60” that is outside the normal range of 0 to 59.
At the direction of the International Earth Rotation & Reference Systems Service (see their bulletin here), the leap second will be introduced after 23:59:59, 30 June 2015. In effect, the clock will read 23:59:60 before it rolls over to 00:00:00, 1 July 2015. This is a one-time event that occurs simultaneously across the globe.
What products will be affected? Unfortunately a lot from all kinds of manufacturers.
Cisco has a list of products here — http://www.cisco.com/web/about/doing_business/leap-second.html#~ProductInformation,
I would pay very close attention as the result of this 61st second in many of the bugs listed is the system crashing or hanging. Check your product versions against the bug lists.
A quick glance of products I work with regularly the following products affected:
- CUCM < 8.0
- CUC < 10
- CER < 11
- VCS/Expressway < 8.5.2
- UCCX < 10.5
- UCS-Manager < 2.2(3e)
- Nexus 9000 = 7.0(3)I1(1.179)
Take a look at the list and implement the various patches or workarounds to avoid undesired outages. Fun fun!