-*- outline -*-

* System timer and system time.

** Windows.

Windows assume that system timer display locale time.

** Debian.

UTC=no - system timer display locale time, UTC=yes - UTC time.

  $ cat /etc/default/rcS
  UTC=no
or
  UTC=yes

If system dual boot with Windows you must set UTC=no.

* Getting current date/time.

  $ date +"%Y-%m-%d %H:%M:%S"

* Setting current date/time.

  $ sudo date --set="2009-02-22 12:12:00" +"%Y-%m-%d %H:%M:%S"

Or set utc time:

  $ sudo date --utc --set="2009-02-22 12:12:00" +"%Y-%m-%d %H:%M:%S"

May be prefer use ntpdate(8) command.

* Get timezone.

System wide configuration:

  $ cat /etc/timezone

* Get list of supported timezone.

  $ tzselect

* Set timezone.

  $ sudo tzconfig
Your current time zone is set to Europe/Kiev
Do you want to change that? [n]: y

Please enter the number of the geographic area in which you live:

    1) Africa           7) Australia
    2) America          8) Europe
    3) US time zones    9) Indian Ocean
    4) Canada time zones 10) Pacific Ocean
    5) Asia             11) Use System V style time zones
    6) Atlantic Ocean   12) None of the above

Number: 8

Then you will be shown a list of cities which represent the time zone
in which they are located. You should choose a city in your time zone.

Amsterdam Andorra Athens Belfast Belgrade Berlin Bratislava Brussels
Bucharest Budapest Chisinau Copenhagen Dublin Gibraltar Guernsey Helsinki
Isle_of_Man Istanbul Jersey Kaliningrad Kiev Lisbon Ljubljana London
Luxembourg Madrid Malta Mariehamn Minsk Monaco Moscow Nicosia Oslo Paris
Podgorica Prague Riga Rome Samara San_Marino Sarajevo Simferopol Skopje
Sofia Stockholm Tallinn Tirane Tiraspol Uzhgorod Vaduz Vatican Vienna
Vilnius Volgograd Warsaw Zagreb Zaporozhye Zurich

Please enter the name of one of these cities or zones
You just need to type enough letters to resolve ambiguities
Press Enter to view all of them again

Name: [] Kiev

Your default time zone is set to 'Europe/Kiev'.
Local time is now:      Sun Feb 22 12:40:16 EET 2009.
Universal Time is now:  Sun Feb 22 10:40:16 UTC 2009.
Your current time zone is set to Europe/Kiev

Or using tzselect:

  $ sudo 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.
#? 8
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
#? 48
Please select one of the following time zone regions.
1) most locations	   3) Zaporozh'ye, E Lugansk
2) Ruthenia		   4) central Crimea
#? 1

The following information has been given:

	Ukraine
	most locations

Therefore TZ='Europe/Kiev' will be used.
Local time is now:	Mon Mar 30 17:25:21 EEST 2009.
Universal Time is now:	Mon Mar 30 14:25:21 UTC 2009.
Is the above information OK?
1) Yes
2) No
#? 1

You can make this change permanent for yourself by appending the line
	TZ='Europe/Kiev'; export TZ
to the file '.profile' in your home directory; then log out and log in again.

Here is that TZ value again, this time on standard output so that you
can use the /usr/bin/tzselect command in shell scripts:
Europe/Kiev

** Debian Lenny.

  $ sudo dpkg-reconfigure tzdata