Hi,
Last time it hurt us badly.
I assume problem has been fixed but… better save than sorry.
Just wanna ask if the fix is still present in the code
and haven’t been lost during recent updates. 
FYI, next leap second date:
December 31 2016 23:59:60 UTC
And at what ROS version was it fixed?
Last time affected were only CCRs (RouterOS v6).
I am pretty sure I am safe, have some CCR’s still on e.g 6.29 happily chugging along. - but just want to check which version it was fixed in - so I can double check.
Wasn’t hard to find:
http://forum.mikrotik.com/t/leap-second-issue-on-ccr-units/89290/1
Unfortunately, there was a bug in our NTP package that caused a crash on CCR units due to the introduction of the Leap Second on June 30, 2015. This bug did not cause any other problems. We have fixed the issue in RouterOS v6.30rc26. No other devices were affected, only CCR units.
Thanks Sigh looks like I will need to upgrade a few, oh well.