易记笔记-Ubuntu系统时间更改

纯粹是为了记录不常用，但是偶尔又会用到的修改系统时间的方法：

一、查看Ubuntu时间的方法 date -R

二、修改Ubuntu系统时间时区sudo tzselect

Please identify a location so that time zone rules can be set correctly.
Please select a continent, ocean, "coord", or "TZ".
 1) Africa
 2) Americas
 3) Antarctica
 4) Asia
 5) Atlantic Ocean
 6) Australia
 7) Europe
 8) Indian Ocean
 9) Pacific Ocean
10) coord - I want to use geographical coordinates.
11) TZ - I want to specify the time zone using the Posix TZ format.
#? 4
Please select a country whose clocks agree with yours.
 1) Afghanistan           18) Iraq                  35) Pakistan
 2) Antarctica            19) Israel                36) Palestine
 3) Armenia               20) Japan                 37) Philippines
 4) Azerbaijan            21) Jordan                38) Qatar
 5) Bahrain               22) Kazakhstan            39) Russia
 6) Bangladesh            23) Korea (North)         40) Saudi Arabia
 7) Bhutan                24) Korea (South)         41) Singapore
 8) Brunei                25) Kuwait                42) Sri Lanka
 9) Cambodia              26) Kyrgyzstan            43) Syria
10) China                 27) Laos                  44) Taiwan
11) Cyprus                28) Lebanon               45) Tajikistan
12) East Timor            29) Macau                 46) Thailand
13) Georgia               30) Malaysia              47) Turkmenistan
14) Hong Kong             31) Mongolia              48) United Arab Emirates
15) India                 32) Myanmar (Burma)       49) Uzbekistan
16) Indonesia             33) Nepal                 50) Vietnam
17) Iran                  34) Oman                  51) Yemen
#? 10
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.
Selected time is now:   Wed Dec  7 17:27:16 CST 2022.
Universal Time is now:  Wed Dec  7 09:27:16 UTC 2022.
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

以上为选择Asia\China\Shanghai 时间。

三、执行命令sudo cp /usr/share/zoneinfo/Asia/Chongqing /etc/localtime替换以前的配置文件。

四、执行sudo hwclock --systohc将时间写入cmos硬件时钟。

五、最后执行sudo date -R 查看系统时间是否更新为正确时间。

这里需要注意“R”为大写。