[tz] Best practices for upcoming leap second event

[Paul Eggert]

If you're responsible for proper timekeeping you probably have already thought 
about the upcoming leap second at the end of Tuesday 2015-06-30 UTC.  This is 
the first leap second in eighteen years that has fallen on a non-holiday 
weekday.  It might not hurt to run through your checklist again, and (if you 
haven't already done so) compare it to the checklist recommended by GPS.GOV, 
NAVCEN, NCCIC, NIST, and USNO.  You can find that checklist here:

http://www.gps.gov/news/2015/05/leap-second/2015-best-practices-for-leap-second.pdf

The new leap second has been in the tz database since release 2015a dated 
2015-01-29 22:35:20 -0800, so if you're newer than that you should be good as 
far as tz is concerned.  In the typical case where you're not using tz's 
leap-second support, you don't need to worry about tz at all.