I recently got a server at home, engaged in external network mapping, installed virtual machines, and found that there was a problem with the time, so I made a little adjustment.
Sync time zone
- [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 Apr 17 20:46:49 CST 2020.
Universal Time is now: Fri Apr 17 12:46:49 UTC 2020.
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
- [root@localhost ~]# TZ='Asia/Shanghai'; export TZ
- [root@localhost ~]# date
System time and hardware time synchronization
[root@localhost ~]# hwclock --show
Fri 17 Apr 2020 08:50:50 PM CST -0.198298 seconds
[root@localhost ~]# hwclock --systohc
If the above two methods do not work after execution, it can be solved like this
It may be caused by this reason:
[root@localhost ~]# date
Fri Apr 17 10:08:56 EDT 2020
EDT:
Refers to Eastern Daylight Time in the United States. Boston, New York City, and Washington, D.C. are all in this time zone, which is 12 hours behind Beijing time, 12 hours later.
CST:
Can refer to the following two:
-
- Central American Standard Time (West Sixth District, -6: 00), China is Eastern Eight District (+8: 00), Beijing Time is 14 hours earlier than Central American Standard Time. 3:45 PM CST is 1:45 AM Beijing time.
-
- Central Australia Standard Time (+10: 30), China is the East Eight District (+8: 00), Beijing time is two and a half hours later than Central Australia Standard Time. 3:45 PM CST is 5:45 am Beijing time.
Then, as long as it is changed to Beijing time zone CST, the modification is as follows:
[root@localhost ~]# ntpdate time.windows.com
17 Apr 10:13:37 ntpdate[5752]: adjust time server 40.81.94.65 offset -0.008618 sec
If you execute the above command prompt: -bash: ntpdate: command not found
then execute the command yum install ntpdate
installationntpdate
[root@localhost ~]# mv /etc/localtime /etc/localtime.bak
[root@localhost ~]# ln -s /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
[root@localhost ~]# date
Fri Apr 17 22:14:01 CST 2020
[root@localhost ~]# ntpdate time.windows.com
17 Apr 22:14:10 ntpdate[5768]: adjust time server 40.81.94.65 offset 0.005776 sec