How do I report an incorrect timezone?

Question

Timezone information for Cayman Islands is incorrect.

The Cayman Islands government toyed with the idea of changing the timezone to have daylight savings, in effect matching US/Eastern time, however this did not come to fruition.

As such, when daylight savings in US/Eastern time started this weekend just gone by (13 March 2016), but not in Cayman, the time in Cayman is now off by 1 hour.

As a work around we've had to change timezones from "Cayman" to "Jamaica".

sudo mv /etc/localtime /etc/localtime.bak
sudo ln -s /usr/share/zoneinfo/Jamaica /etc/localtime

This is obviously not a permanent solution.

• What should I do to fix this permanently?
• How / who do I report this error to?

Answer 1

Time Zone data 2016a already takes this into account:

America/Cayman will not observe daylight saving this year after all. Revert our guess that it would. (Thanks to Matt Johnson.)

All that needs to happen now is for your distribution to update its time-zone data. You can check whether a bug has already been filed in your distribution's bug tracker, and file one if necessary...

In the meantime you can also download the updated tarball and use that to update your zoneinfo file.

Answer 2

The timezone database used by, well, everybody is maintained by IANA. They've already updated their database. The best solution is for you to upgrade your system; most distributions should provide an updated package when the timezone database changes.

If for some reason you can't easily update your system to install the latest version of the timezone database, you can declare the timezone through the TZ environment variable, which has the advantage of requiring no installation of any kind, but the downside that it requires an explicit setting so it won't help applications that work on multiple timezones.

export TZ='EST+5'

On a system with Glibc (i.e. non-embedded Linux), an alternative is to retrieve the latest timezone database and set TZ to :/path/to/zoneinfo/American/Cayman (i.e. the path to the file with a leading colon). This has the benefit of being aware of any historical change that the timezone database knows about, whereas the direct form only knows the current rules so would get historical times wrong.