Centos7 如何修改时间和时区

首先查看一下当前的时间，

#date 
Thu May 30 23:45:18 EDT 2019

系统时间和当前时间明显不一样，最简单的办法就是更新一下网络时间，前提是系统能够连网，

自行修改时间方法：

#date -s "20170402 19:00:00"

同步网络时间方法： 首先安装ntpdate工具

#yum -y install ntp ntpdate 
#ntpdate cn.pool.ntp.org #设置系统时间与网络时间同步 
#hwclock --systohc #将系统时间写入硬件时间

更改硬件时间：

#hwclock --show /sbin/
#hwclock --systohc

修改时区

#timedatectl set-timezone Asia/Shanghai

或者

#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 31 11:44:44 CST 2019.
Universal Time is now:  Fri May 31 03:44:44 UTC 2019.
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
#cp /usr/share/zoneinfo/Asia/Shanghai /etc/localtime