Linux Daylight Saving Time

How to : DST settings on Redhat 4.0 and any other OS.

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.

(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
OR
# cp /usr/share/zoneinfo/ America/NewYork /etc/localtime
# zdump -v /etc/localtime |grep 2008

If you are running Debian/Ubuntu Linux...

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

Run tzconfig to update your configuration:
# tzconfig
# zdump -v /etc/localtime |grep 2008


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).