$ date
Sat Jun 27 13:24:49 KST 2020
$ sudo hwclock -s
$ date
Sat Jun 27 13:27:35 KST 2020
$ ntpdate
Command 'ntpdate' not found, but can be installed with:
sudo apt install ntpdate
sudo apt install ntpsec-ntpdate
$ sudo apt install ntpdate
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed:
ntpdate
0 upgraded, 1 newly installed, 0 to remove and 45 not upgraded.
Need to get 51.8 kB of archives.
After this operation, 183 kB of additional disk space will be used.
Get:1 http://mirror.kakao.com/ubuntu bionic-updates/universe amd64 ntpdate amd64 1:4.2.8p10+dfsg-5ubuntu7.1 [51.8 kB]
Fetched 51.8 kB in 0s (575 kB/s)
Selecting previously unselected package ntpdate.
(Reading database ... 119629 files and directories currently installed.)
Preparing to unpack .../ntpdate_1%3a4.2.8p10+dfsg-5ubuntu7.1_amd64.deb ...
Unpacking ntpdate (1:4.2.8p10+dfsg-5ubuntu7.1) ...
Setting up ntpdate (1:4.2.8p10+dfsg-5ubuntu7.1) ...
Processing triggers for man-db (2.8.3-2ubuntu0.1) ...
$ sudo ntpdate
27 Jun 13:29:36 ntpdate[6683]: no servers can be used, exiting
$ sudo ntpdate pool.ntp.org
27 Jun 22:30:01 ntpdate[6690]: step time server 211.233.84.186 offset 32401.761532 sec
$ date
Sat Jun 27 22:30:04 KST 2020