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Howto: Redhat enterprise Linux setup DST – Daylight Saving Time

Wikipedia defines DST as follows:
Daylight saving time (DST), also known as summer time in British English, is the convention of advancing clocks so that evenings have more daylight and mornings have less. Typically clocks are adjusted forward one hour in late winter or early spring and are adjusted backward in autumn. Details vary by location and change occasionally; see When it starts and stops below.

Do I need to apply the DST patch on my server?

DST patch is only required in few countries such as North America countries (e.g. United States. DST is not required in India and Asia (China, Hong Kong, Macau, Taiwan) at all (however once we had DST). Please see this wikipedia article. It display usage and a short history of daylight saving time by location in alphabetic order.

Daylight Saving Time map image worldwild
(See DST heat map)

Do I need to apply the DST patch on AIX/UNIX/Linux/HP-UX/Solaris/Windows servers running in IST (Indian) timezone?

I’ve received at least 8-10 email regarding IST timetonze. Short answer is no (see heat map).

Task: Verify if you need DST update i.e. display timezone data

Use the zdump utility to display timezone data.
# zdump -v Australia/Queensland
# zdump -v /etc/localtime | grep 2007

If you see date “Sun Mar 11” your system is already patched and no need to read further.

Many of our servers located in north America and all of these server powered by RedHat enterprise Linux or Debian Linux or MS-Windows server 2003.

If you are running RHEL 4.0...

Update tzdata package:
# up2date -u tzdata
# system-config-date

# cp /usr/share/zoneinfo/ America/NewYork /etc/localtime
# zdump -v /etc/localtime |grep 2007

If you are running Debian/Ubuntu Linux...

Use apt-get to update tzdata package:
$ sudo apt-get install tzdata
# apt-get install tzdata

Run tzconfig to update your configuration:
# tzconfig
# zdump -v /etc/localtime |grep 2007

Microsoft Window Server / XP DST

Please see - how to configure daylight saving time for the United States in 2007

Sun Java and DST

A few servers running Sun Java requires update as well.

Manually update DST under Linux

You can manually update your configuration by following these inductions as well.

Check DST using a Webbrowser

You can also check your Linux or Windows workstation by visiting the University of Minnesota's DST time check site (browser with javascript support required).

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{ 3 comments… add one }

  • Alexis August 6, 2007, 6:09 am

    Thank you Vivek for this great info.I appreciate your wonderful articles.

    I have been wondering whether DST really saves energy:
    I think this is paradoxical because on one hand there is a little bit energy which is saved but on the other hand lots of companies waste their resources(time and money) creating patches for their systems.People in countries which apply DST have to reschedule their time(at the beginning and the end of DST), on-line meeting,etc. This is really disturbing.
    What do you think about this?

  • Appaji November 13, 2007, 1:11 pm

    The description is quite useful for me. Still I have few doubts regarding DST.
    How can I check (in Linux) whether DST is enabled or not currently in the system zone?
    Is there any way to disable and enable DST feature manually even for US zones?

  • Simon June 8, 2010, 4:43 pm

    British English… as in regular English?

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