Linux / UNIX: Set The Time Zone On a Per User Basis

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We are developing Linux based application and we would like to set the time zone on a per user basis for individual user. How do I configure Fedora Linux or any Unix like oses to set the time zone on a per user basis using bash shell?

A time zone is a region of the Earth that has adopted the same standard time, usually referred to as the local time. Most adjacent time zones are exactly one hour apart, and by convention compute their local time as an offset from Greenwich Mean Time.

You can set the time zone system-wide using this method. However use following instructions to set the time zone on a per user basis.

Most Unix based systems, including Linux and Mac OS X, keep system time as UTC. Rather than having a single timezone set for the whole computer, timezone offsets can vary for different processes. Standard library routines are used to calculate the local time based on the current timezone, normally supplied to processes through the TZ environment variable. This allows users in multiple timezones to use the same computer, with their respective local times displayed correctly to each user. Timezone information is most commonly stored in a timezone database known as zoneinfo

Procedure – set the time zone on a per user basis

Open user ~/.bashrc or ~/.bash_profile file using a text editor such as and set up TZ environment variable. Append or SET TZ as follows:

export TZ="/usr/share/zoneinfo/{TIMEZONE-DIRECTORY}/{TIMEZONE_FILE}"

If your username is vivek and you would like to set TZ to Asia/Calcutta (INDIA IST) type the following command:
$ vi /home/vivek/.bashrc
OR
$ vi ~/.bashrc
Append the following line:
export TZ="/usr/share/zoneinfo/Asia/Calcutta"
Save and close the file. You can type the same command at bash shell prompt too:

export TZ="/usr/share/zoneinfo/Asia/Calcutta"

See also:

  • Set the time zone system-wide using this /etc/localtime file

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin and a trainer for the Linux operating system/Unix shell scripting. He has worked with global clients and in various industries, including IT, education, defense and space research, and the nonprofit sector. Follow him on Twitter, Facebook, Google+.

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5 comment

  1. The above steps don’t seem to work well.

    Please check the link http://rai.amalji.com/timecheck.php

    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~`
    [[email protected] rai]# cat timecheck.php
    <?php

    echo “Present time in (India IST) is : “.date(“d D, M Y – h:i:s A”).””;
    ?>
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~`
    [[email protected] rai]# ll .bash
    .bash_profile .bashrc

    [[email protected] rai]# cat .bash*
    export TZ=”/usr/share/zoneinfo/Asia/Calcutta”
    export TZ=”/usr/share/zoneinfo/Asia/Calcutta”
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~`

    Please check the correct time comparisons from :
    http://www.amalji.com/time

    Fix:

    Use php : http://rai.amalji.com/timecheck1.php
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~`
    <?PHP

    putenv(“TZ=Asia/Calcutta”);
    echo “Present time in (India IST) is : “.date(“d D, M Y – h:i:s A”).””;
    ?>
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~`

    I’d appreciate if you let me know what was wrong. :-)

    Rai

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