Time Management for Linux systems

Time Management for Linux systems

1 Viewing system time and date: date

[Email protected] desktop]# date Tue June 2 05:25:05 EDT 2015

2 View hardware time: Hwclock--show | -R

[Email protected] desktop]# hwclock Tue 05:40:30 AM EDT-0.272377 seconds

3 Modify the command used by the system time:

To modify the system time:

[[email protected] named]# date-s "6/1/2015 18:00:00" #设置为6月/1st/2015 year: minute: Mon June 1 18:00:00 EDT 2015[[email protected] named]# date-s "11:11:11 2011-10-3" #这样也行Mon Oct 3 11:11:11 CST 2011

To modify the system hardware time:

[Email protected] desktop]# hwclock--set--date= "06/18/14 14:55" [[email protected] desktop]# Hwclock-r # #相当于hwclock --showwed June 02:55:22 PM EDT-0.569262 seconds

4 Write the time and date of the current system to the BIOS to avoid failure after reboot: Hwclock-w

[Email protected] desktop]# hwclock-w

Attention:

Hwclock

# #将系统时间设置为当前硬件的时间

-S,--hctosys set the system time from the hardware clock

# #将硬件的时间设置为当前系统的时间

-W,--SYSTOHC set the hardware clock from the current system time

5 time zone changes: tzselect

Tzselect just prompts us to choose the time zone, which will not actually take effect, but we can follow the instructions.

[[Email protected] desktop]# 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 ocean10)  pacific ocean11)  none  - i want to specify the time zone using the posix  tz format.#? 5please select a country. 1)  Afghanistan  18)  israel    35) ( palestine 2)  armenia  19)  Japan     36) ( philippines 3)  azerbaijan  20)  Jordan     37)  qatar 4)  bahrain  21) &nbsP kazakhstan    38)  russia 5)  bangladesh  22)  Korea  ( North)     39)  saudi arabia 6)  bhutan  23)  Korea  ( South)     40)  singapore 7)  brunei  24)  Kuwait     41) ( sri lanka 8)  cambodia  25)  Kyrgyzstan     42)  syria 9)  china  26)  laos    43)  Taiwan10)  cyprus  27)  lebanon    44)  tajikistan11)  East Timor   28) ( macau    45)  thailand12)  georgia  29)   malaysia    46)  turkmenistan13)  hong kong  30)  Mongolia     47)  united arab emirates14)  india  31)  Myanmar   (Burma)     48) &nbSp UZBEKISTAN15)  indonesia  32)  nepal    49)  vietnam16)  Iran   33)  oman    50)  yemen17)  iraq  34)  Pakistan#?  9please select one of the following time zone regions.1)   EAST CHINA - BEIJING, GUANGDONG, SHANGHAI, ETC.2)  Heilongjiang  (except  mohe),  jilin3)  central china - sichuan, yunnan, guangxi, shaanxi ,  guizhou, etc.4)  most of tibet & xinjiang5)  west Tibet  & Xinjiang#? 1The following information has been given:Chinaeast  China - beijing, guangdong, shanghai, etc. therefore tz= ' Asia/shanghai '  will be used. local time is now:wed jun  3 09:31:59 cst 2015.universal time is now:wed jun  3 01:31:59 utc 2015.is the above  information ok?1)  yes2)  no#? 1   # #以下是一个实际生效的提示You  can make  This change permanent for yourself by appending the linetz= ' Asia/ Shanghai '; export tzto 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 youcan use the /usr/bin/tzselect command in shell  Scripts:asia/shanghai

According to the following hints, it is necessary to tz= ' Asia/shanghai '; Export TZ This line is written to the. Profile configuration file, but I'm used to writing it in the. bashrc file.

[Email protected] ~]# vim/root/.bash_profile # #编辑当前用户的bash环境文件 [[email protected] ~]# cat/root/.bash_profile#. bash_ profile# Get the aliases and Functionsif [-f ~/.BASHRC]; Then. ~/.bashrcfi# User specific environment and startup Programspath= $PATH: $HOME/binexport pathtz= ' Asia/shanghai '; Export TZ # #将时区更改的语句 put it here.

It is recommended that you write the time zone setting in the/ETC/BASHRC file, which takes effect globally.

To view the current time zone:

[Email protected] desktop]# date-rtue, 2015 22:09:31-0400

Refresh and reread. Bash_profile

[Email protected] desktop]# date-rtue, June 22:14:49-0400[[email protected] desktop]# source/root/.bash_profile [Email protected] desktop]# date-r

Wed, June 10:15:10 +0800 # #时区已更改为北京时区

Another way: Modify the configuration file directly

Configuration file for time zone:/etc/localtime

Storage path for all time zone files:/usr/share/zoneinfo

Asia Time zone:/usr/share/zoneinfo/asia

Choose Shanghai time Zone:/usr/share/zoneinfo/asia/shanghai

Link the Shanghai time zone file software to the time zone configuration file/etc/localtime

[Email protected]/]# ln-s/usr/share/zoneinfo/asi a/shanghai/etc/localtime

View Date-r after reboot

Graphical interface:

Redhat 6 or less: System-config-time

Redhat 7:system-config-date

This article is from the "Tiandaochouqin" blog, make sure to keep this source http://luzhi1024.blog.51cto.com/8845546/1657804

Time Management for Linux systems