ubuntu16 Run the command dpkg-reconfigure tzdata, select Asia-->Shanghai, OK,

ubuntu12:

First check the time zone:

swfsadmin@swfsubuntu:~$ date -R
Tue,17 Dec 201318:23:01+0800

If you want to modify the time zone, execute sudo tzselect

Select region: Asia

swfsadmin@swfsubuntu:~$ sudo tzselect
[ sudo] password for swfsadmin: 
Sorry,try again.[sudo] password for swfsadmin: 
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

Select country: China

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

Select time zone: Beijing time

Please select one of the following time zone regions.1) east China - Beijing, Guangdong, Shanghai, etc.2)Heilongjiang(except Mohe), Jilin
3) central China - Sichuan, Yunnan, Guangxi, Shaanxi, Guizhou, etc.4) most of Tibet & Xinjiang
5) west Tibet & Xinjiang
#?1

Confirm verification:

The following information has been given:

  China
  east China - Beijing, Guangdong, Shanghai, etc.

Therefore TZ='Asia/Shanghai' will be used.
Local time is now:      Tue Dec 1718:22:10 CST 2013.
Universal Time is now:  Tue Dec 1710:22:10 UTC 2013.
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

Copy files to the /etc directory

sudo cp /usr/share/zoneinfo/Asia/Shanghai /etc/localtime

Update time

sudo ntpdate time.windows.com

Change time reference:

http://5154091.blog.hexun.com/30735220_d.html

Change the time

sudo date -s MM/DD/YY //Modified date
sudo date -s hh:mm:ss //Change the time

After the modification time, modify the hardware CMOS time

sudo hwclock --systohc //Very important, if there is no such step, the time is still not allowed

How to modify time zone and time in ubuntu

Change time reference: