Changing default date and timezones
There are a few different ways to change the default date and timezone within CentOS operating system for web servers with only command line / SSH access. Below are separate methods outlined for CentOS 6 and CentOS 7. Three useful tutorial links for further reading can be found at:
- http://www.cyberciti.biz/faq/centos-linux-6-7-changing-timezone-command-line/
- http://www.cyberciti.biz/faq/howto-linux-unix-change-setup-timezone-tz-variable/
- http://www.cyberciti.biz/faq/howto-set-date-time-from-linux-command-prompt/
Centmin Mod default method used to change the timezone involves basically one variable in centmin.sh and two lines of commands to run in SSH telnet session.
ZONEINFO=Australia/Brisbane rm -f /etc/localtime ln -s /usr/share/zoneinfo/$ZONEINFO /etc/localtime
The ZONEINFO variable defines the default timezone at Centmin Mod installation time, while the last 2 command lines remove existing localtime and symlinks to ZONEINFO defined preset value.
You can see the full list of possible values for ZONEINFO at /usr/share/zoneinfo. For example, top level
ls /usr/share/zoneinfo/ Africa Australia Cuba Etc GMT0 Iceland Japan MST Poland right Universal Zulu America Brazil EET Europe GMT-0 Indian Kwajalein MST7MDT Portugal ROC US Antarctica Canada Egypt Factory GMT+0 Iran Libya Navajo posix ROK UTC Arctic CET Eire GB Greenwich iso3166.tab MET NZ posixrules Singapore WET Asia Chile EST GB-Eire Hongkong Israel Mexico NZ-CHAT PRC Turkey W-SU Atlantic CST6CDT EST5EDT GMT HST Jamaica Mideast Pacific PST8PDT UCT zone.tab
For Australia:
ls /usr/share/zoneinfo/Australia/ ACT Brisbane Canberra Darwin Hobart Lindeman Melbourne NSW Queensland Sydney Victoria Yancowinna Adelaide Broken_Hill Currie Eucla LHI Lord_Howe North Perth South Tasmania West
For America:
ls /usr/share/zoneinfo/America/ Adak Blanc-Sablon Cordoba Fort_Wayne Inuvik Manaus Montserrat Porto_Velho Shiprock Vancouver Anchorage Boa_Vista Costa_Rica Glace_Bay Iqaluit Marigot Nassau Puerto_Rico Sitka Virgin Anguilla Bogota Cuiaba Godthab Jamaica Martinique New_York Rainy_River St_Barthelemy Whitehorse Antigua Boise Curacao Goose_Bay Jujuy Matamoros Nipigon Rankin_Inlet St_Johns Winnipeg Araguaina Buenos_Aires Danmarkshavn Grand_Turk Juneau Mazatlan Nome Recife St_Kitts Yakutat Argentina Cambridge_Bay Dawson Grenada Kentucky Mendoza Noronha Regina St_Lucia Yellowknife Aruba Campo_Grande Dawson_Creek Guadeloupe Knox_IN Menominee North_Dakota Resolute St_Thomas Asuncion Cancun Denver Guatemala Kralendijk Merida Ojinaga Rio_Branco St_Vincent Atikokan Caracas Detroit Guayaquil La_Paz Metlakatla Panama Rosario Swift_Current Atka Catamarca Dominica Guyana Lima Mexico_City Pangnirtung Santa_Isabel Tegucigalpa Bahia Cayenne Edmonton Halifax Los_Angeles Miquelon Paramaribo Santarem Thule Bahia_Banderas Cayman Eirunepe Havana Louisville Moncton Phoenix Santiago Thunder_Bay Barbados Chicago El_Salvador Hermosillo Lower_Princes Monterrey Port-au-Prince Santo_Domingo Tijuana Belem Chihuahua Ensenada Indiana Maceio Montevideo Porto_Acre Sao_Paulo Toronto Belize Coral_Harbour Fortaleza Indianapolis Managua Montreal Port_of_Spain Scoresbysund Tortola
To view your current date, type 'date' command in SSH telnet:
date Sun Feb 26 01:26:32 EST 2012
To change the timezone, you can either do it same way Centmin Mod default install does it, and remove the /etc/localtime file and symlink it to another ZONEINFO setting:
ZONEINFO=Australia/Brisbane rm -f /etc/localtime ln -s /usr/share/zoneinfo/$ZONEINFO /etc/localtime
Or for CentOS 7.x only you can use thetimedatectl command in SSH telnet. For example to change to Los Angeles timezone:
Find your Zone info code:
timedatectl list-timezones --no-pager | grep 'America\/Los' America/Los_Angeles
Then change it:
timedatectl set-timezone America/Los_Angeles
Verify settings:
date ls -l /etc/localtime
Or for CentOS 6.x only you can use the tzselect command in SSH telnet. For example to change to Bahamas timezone:
You may need to remove the existing symlink before using tzselect
rm -f /etc/localtime
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.
#? 2
Please select a country.
1) Anguilla 28) Haiti
2) Antigua & Barbuda 29) Honduras
3) Argentina 30) Jamaica
4) Aruba 31) Martinique
5) Bahamas 32) Mexico
6) Barbados 33) Montserrat
7) Belize 34) Nicaragua
8) Bolivia 35) Panama
9) Bonaire Sint Eustatius & Saba 36) Paraguay
10) Brazil 37) Peru
11) Canada 38) Puerto Rico
12) Cayman Islands 39) Sint Maarten
13) Chile 40) St Barthelemy
14) Colombia 41) St Kitts & Nevis
15) Costa Rica 42) St Lucia
16) Cuba 43) St Martin (French part)
17) Curacao 44) St Pierre & Miquelon
18) Dominica 45) St Vincent
19) Dominican Republic 46) Suriname
20) Ecuador 47) Trinidad & Tobago
21) El Salvador 48) Turks & Caicos Is
22) French Guiana 49) United States
23) Greenland 50) Uruguay
24) Grenada 51) Venezuela
25) Guadeloupe 52) Virgin Islands (UK)
26) Guatemala 53) Virgin Islands (US)
27) Guyana
#? 5
The following information has been given:
Bahamas
Therefore TZ='America/Nassau' will be used.
Local time is now: Sat Feb 25 10:28:19 EST 2012.
Universal Time is now: Sat Feb 25 15:28:19 UTC 2012.
Is the above information OK?
1) Yes
2) No
#? y
Please enter 1 for Yes, or 2 for No.
#? 1
You can make this change permanent for yourself by appending the line
TZ='America/Nassau'; 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:
America/Nassau
