Friday, 19 July 2013

Centos 6/RHEL install and use Tzdata time zone utilty

Tzdata is a collection of the worlds time zone information and can be used to set the time for individual users on a Linux system.

To use it first download the tzdata package from the repo.

$ sudo yum -y install tzdata

$ tzselect

Please identify a location so that time zone rules can be set correctly.
Please select a continent or ocean.
 1) Africa
 2) Americas
 3) Antarctica
 4) Arctic Ocean
 5) Asia
 6) Atlantic Ocean
 7) Australia
 8) Europe
 9) Indian Ocean
10) Pacific Ocean
11) none - I want to specify the time zone using the Posix TZ format.
#? 


Select a value and press the return key to proceed.

You will now be asked a country to select from the list provided.

Please select a country.
 1) Aaland Islands        18) Greece                35) Norway
 2) Albania               19) Guernsey              36) Poland
 3) Andorra               20) Hungary               37) Portugal
 4) Austria               21) Ireland               38) Romania
 5) Belarus               22) Isle of Man           39) Russia
 6) Belgium               23) Italy                 40) San Marino
 7) Bosnia & Herzegovina  24) Jersey                41) Serbia
 8) Britain (UK)          25) Latvia                42) Slovakia
 9) Bulgaria              26) Liechtenstein         43) Slovenia
10) Croatia               27) Lithuania             44) Spain
11) Czech Republic        28) Luxembourg            45) Sweden
12) Denmark               29) Macedonia             46) Switzerland
13) Estonia               30) Malta                 47) Turkey
14) Finland               31) Moldova               48) Ukraine
15) France                32) Monaco                49) Vatican City
16) Germany               33) Montenegro
17) Gibraltar             34) Netherlands
 

Select and confirm the selection with 1 for Yes.

This completes the setup but to make it permanent you should add the following  line to your ~/.bashrc file.

TZ='Europe/London'; export TZ

Then log out and back in again. 

The user can now log in and run the date command

$ date 


Fri Jul 19 14:56:53 BST 20

Other commands

Set the date to 19th July 2013

Syntax is date --set="YYYYMMDD"

$ date --set="20130719" 

Fri Jul 19 00:00:00 BST 2013

Set the time to 14.10

Syntax is date +%T -s "HH:MM:SS"

$ date +%T -s "14:10:34"

14:10:34

See also OpenNTPD