查看时间

#查看系统时间 - 12 小时制
root@ubuntu20:/# date
Wed 01 Sep 2021 11:51:26 PM CST

#查看系统时间 - 24 小时制
root@ubuntu20:/# date -R
Wed, 01 Sep 2021 23:51:29 +0800

#查看硬件时间
root@ubuntu20:/# hwclock --show
2021-09-02 00:16:11.773346+08:00

root@ubuntu20:/#

时间自动更新设置

查看

root@ubuntu20:~# timedatectl show
Timezone=Etc/UTC
LocalRTC=no
CanNTP=yes
NTP=no
NTPSynchronized=no
TimeUSec=Thu 2021-09-02 00:08:33 CST
RTCTimeUSec=Thu 2021-09-02 00:08:36 CST

root@ubuntu20:~# 

NTP=no  表示时间的自动更新是关闭的

NTP=yes  表示时间的自动更新是开启的

关闭

root@ubuntu20:~# timedatectl set-ntp no

root@ubuntu20:~# timedatectl show
Timezone=Etc/UTC
LocalRTC=no
CanNTP=yes
NTP=no
NTPSynchronized=no
TimeUSec=Thu 2021-09-02 00:12:00 CST
RTCTimeUSec=Thu 2021-09-02 00:12:04 CST

root@ubuntu20:~#

打开

root@ubuntu20:~# timedatectl set-ntp yes

root@ubuntu20:~# timedatectl show
Timezone=Etc/UTC
LocalRTC=no
CanNTP=yes
NTP=yes
NTPSynchronized=yes
TimeUSec=Wed 2021-09-01 11:16:47 CST
RTCTimeUSec=Wed 2021-09-01 11:16:46 CST

root@ubuntu20:~#

系统时区列表

timedatectl list-timezones

设置时区

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

时区文件目录 /usr/share/zoneinfo

root@ubuntu20:/etc# cd /usr/share/zoneinfo
root@ubuntu20:/usr/share/zoneinfo# ls
Africa      Asia       Canada   Cuba   EST      Factory  GMT+0      Hongkong  Iran         Japan              Libya      MST      NZ-CHAT   posix       right      SystemV    Universal  W-SU
America     Atlantic   CET      EET    EST5EDT  GB       GMT-0      HST       iso3166.tab  Kwajalein          localtime  MST7MDT  Pacific   posixrules  ROC        Turkey     US         zone1970.tab
Antarctica  Australia  Chile    Egypt  Etc      GB-Eire  GMT0       Iceland   Israel       leapseconds        MET        Navajo   Poland    PRC         ROK        tzdata.zi  UTC        zone.tab
Arctic      Brazil     CST6CDT  Eire   Europe   GMT      Greenwich  Indian    Jamaica      leap-seconds.list  Mexico     NZ       Portugal  PST8PDT     Singapore  UCT        WET        Zulu

root@ubuntu20:/usr/share/zoneinfo# cd Asia
root@ubuntu20:/usr/share/zoneinfo/Asia# ls
Aden      Ashkhabad  Beirut      Chungking  Dushanbe     Hovd       Kamchatka  Krasnoyarsk   Makassar      Oral        Rangoon    Singapore      Thimbu         Urumqi         Yerevan
Almaty    Atyrau     Bishkek     Colombo    Famagusta    Irkutsk    Karachi    Kuala_Lumpur  Manila        Phnom_Penh  Riyadh     Srednekolymsk  Thimphu        Ust-Nera
Amman     Baghdad    Brunei      Dacca      Gaza         Istanbul   Kashgar    Kuching       Muscat        Pontianak   Saigon     Taipei         Tokyo          Vientiane
Anadyr    Bahrain    Calcutta    Damascus   Harbin       Jakarta    Kathmandu  Kuwait        Nicosia       Pyongyang   Sakhalin   Tashkent       Tomsk          Vladivostok
Aqtau     Baku       Chita       Dhaka      Hebron       Jayapura   Katmandu   Macao         Novokuznetsk  Qatar       Samarkand  Tbilisi        Ujung_Pandang  Yakutsk
Aqtobe    Bangkok    Choibalsan  Dili       Ho_Chi_Minh  Jerusalem  Khandyga   Macau         Novosibirsk   Qostanay    Seoul      Tehran         Ulaanbaatar    Yangon
Ashgabat  Barnaul    Chongqing   Dubai      Hong_Kong    Kabul      Kolkata    Magadan       Omsk          Qyzylorda   Shanghai   Tel_Aviv       Ulan_Bator     Yekaterinburg

root@ubuntu20:/usr/share/zoneinfo/Asia#

设置系统时间

#设置系统时间
date -s "2021-09-01 23:50:00"

#将系统时间同步到硬件时间
hwclock --systohc