Ubuntu 设置系统时区

最简单直接的方法：

timedatectl set-timezone Asia/Shanghai

传统方法：

tzselect

按提示逐步操作：

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 timezone using the Posix TZ format.

#? 4

Please select a country whose clocks agree with yours.
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 timezones.
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:	Mon Mar 29 12:53:57 CST 2021.
Universal Time is now:	Mon Mar 29 04:53:57 UTC 2021.
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

最后设置系统时区：

sudo ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime