To updated the timezone files:

1- get the vzic tool from https://github.com/libical/vzic

2- update the Makefile

  PRODUCT_ID = -//Inverse inc.//NONSGML IANA 2016h//EN
  TZID_PREFIX =

3- get the zone files, for example:

  mkdir /tmp/zones
  cd /tmp/zones
  wget http://www.iana.org/time-zones/repository/releases/tzdata2016i.tar.gz
  tar -zxvf tzdata2016i.tar.gz

4- compile and run the conversion tool

  make -B
  ./vzic --olson-dir /tmp/zones --output-dir ../SOGo/SOPE/NGCards/TimeZones/

5- cleanup

  cd ../SOGo/SOPE/NGCards/TimeZones/
  rm -f zones.h zones.tab
