Sometimes a couple countries decides to change the future datetime interval that the country will use as referencial time to jump from CST to CDT or DST to CST, so for that case is important have all the servers in sync, so the best way is to update the timezone list of each server.
The file provides all the major regions time zones with the current update history versions within http://www.iana.org/time-zones
Time Zone Database
The Time Zone Database (often called tz or zoneinfo) contains code and data that represent the history of local time for many representative locations around the globe.
Procedure to update time Zone list in Linux