centos7 修改时间、时区问题

如果发现系统时间不正常、时区错误，可以使用tzselect命令设置。
[root@localhost /]# 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.

? 5

Please select a country.
1) Afghanistan 18) Israel 35) Palestine
2) Armenia 19) Japan 36) Philippines
3) Azerbaijan 20) Jordan 37) Qatar
4) Bahrain 21) 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) Taiwan
10) Cyprus 27) Lebanon 44) Tajikistan
11) East Timor 28) Macau 45) Thailand
12) Georgia 29) Malaysia 46) Turkmenistan
13) Hong Kong 30) Mongolia 47) United Arab Emirates
14) India 31) Myanmar (Burma) 48) Uzbekistan
15) Indonesia 32) Nepal 49) Vietnam
16) Iran 33) Oman 50) Yemen
17) Iraq 34) Pakistan

? 9

Please select one of the following time zone regions.
1) Beijing Time
2) Xinjiang Time

? 1

The following information has been given:

    China
    Beijing Time

Therefore TZ=’Asia/Shanghai’ will be used.
Local time is now: Fri May 20 23:36:08 CST 2016.
Universal Time is now: Fri May 20 15:36:08 UTC 2016.
Is the above information OK?
1) Yes
2) No

? 1

You can make this change permanent for yourself by appending the line
TZ=’Asia/Shanghai’; 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:
Asia/Shanghai

设置完全后，再使用ntpdate命令与时间服务器同步一下系统时间
[root@localhost ~]# ntpdate us.pool.ntp.org
-bash: ntpdate: command not found

[root@localhost ~]# yum install ntpdate
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: mirrors.btte.net
* extras: mirrors.nwsuaf.edu.cn
* updates: mirrors.nwsuaf.edu.cn
……….
Installed:
ntpdate.x86_64 0:4.2.6p5-22.el7.centos.1

Complete!
安装完成 ，开始同步
[root@localhost ~]# ntpdate cn.ntp.org.cn
20 May 15:26:37 ntpdate[1680]: adjust time server 110.75.186.249 offset 0.139888 sec

同步成功，验证系统时间及时区。
[root@localhost ~]# date
Fri May 20 15:26:50 CST 2016
[root@localhost ~]# date -R
Fri, 20 May 2016 15:27:41 +0800