Red Hat Bugzilla – Bug 244165
invalid timezones Etc/GMT-13, Etc/GMT-14
Last modified: 2015-05-04 21:33:14 EDT
Description of problem: According to: http://www.worldtimezone.com/index24.php http://wwp.greenwichmeantime.com/time-zone/time-zones.htm there is no timezone GMT-13, GMT-14, officially there are 25 timezones: GTM, GMT+/-12 Version-Release number of selected component (if applicable): system-config-date-1.8.12-1.el5 How reproducible: Always Steps to Reproduce: 1. run system-config-date 2. choose teb "Time zone" 3. expand "Non geographic timezones" Actual results: There are Etc/GMT-13 and Etc/GMT-14 timezones. Expected results: There should be timezones up to GMT+/-12 only. Additional info: This affect Anaconda because it uses system-config-date to allow time zone settings before installation.
system-config-date uses all the timezones found beneath /usr/share/zoneinfo, e.g. the "Etc/GMT-13" timezone corresponds with the file /usr/share/zoneinfo/Etc/GMT-13 which is contained in the tzdata package -> changing component.
$ rpm -q tzdata tzdata-2007d-1.el5
GMT time zones used to be the only alternative for countries that were not covered by the zoneinfo "proper" zones. By now, most of the inhabited world is covered by proper zones, but GMT zones remain for backwards compatibility, and for nautical use. The -13 and -14 zones in particular were used for countries that are on the edge of the international date line, so that they are don't end up having different dates on east and west coast. They have no nautical use, because, as you said, only -12..+12 makes sense in general; so I guess they are only present for backwards compatibility.
As there is not official timezone GMT-13/14 how do these countries solve the issue. IMO they stick to some of the official zones. I think this is problem is in the competency of those who define timezones. As software dewelopers we don't have to solve the problems but stick to the rules.