man tzconfig (Administration système) - set the local timezone
NAME
tzconfig - set the local timezone
SYNOPSIS
tzconfig
DESCRIPTION
This manual page explains how you can use the tzconfig utility to set the local timezone. This is necessary to let your system know about the difference between system time and local time (the time in the real world). It is also necessary to make your system behave nicely when your location uses Daylight Savings Time.
A valid system time together with the correct local time zone will give you best performance and highest reliability. It is especially important in a network environment, where even small time differences can make a mirror refetch a whole ftp site, or where time stamps on external file systems are used.
tzconfig is called without any parameters from the shell. First it presents the current setting and asks for verification to change it.
You may press Ctrl-C to interrupt the script at any time.
After you made your choice, tzconfig will try to change the timezone for you. See the Internals section below for technical details. You must have root privileges to actually change anything. Please use tzselect(1) as a user space command to just look at the timezones. It will print the local time in any timezone recognized by the system.
A WORD OF WARNING
What timezone is correct for your system? It depends on the geographical location of the machine. Getting the correct location is important, but the system must also know how your hardware clock is set. Most DOS based PCs set their hardware clock on Local Time, while most UNIX systems set their hardware clock to UTC.
The Debian GNU/Linux system gains its knowledge of this setting from the file /etc/default/rcS. This file contains either the line UTC=yes, which indicates that the hardware clock is set to UTC, or it contains the line UTC=no, which declares the hardware clock is set to Local Time. If these setting are correct, and the hardware clock is truly set as indicated, then configuring the proper timezone for the machine will cause the proper date and time to be displayed. If these are not set correctly, the the reported time will be quite incorrect. See hwclock(8) for more details on this topic.
Internals
The work done by tzconfig is actually pretty simple. It just updates the link /etc/localtime to point to the correct timezone installed in /usr/share/zoneinfo/.
There is nothing wrong with doing this manually. However, using tzconfig you don't have to remember the path to the timezones.
FILES
/etc/timezone /etc/localtime /usr/share/zoneinfo
SEE ALSO
AUTHOR
Copyright 1998 Marcus Brinkmann <brinkmd@debian.org> Edits Copyright 1998 Dale Scheetz <dwarf@polaris.net>
Please see nroff source for legal notice.