# 查看系统时间状态
$ timedatectl
Local time: Thu 2026-04-03 10:40:15 CST
Universal time: Thu 2026-04-03 02:40:15 UTC
RTC time: Thu 2026-04-03 02:40:15
Time zone: Asia/Shanghai (CST, +0800)
System clock synchronized: yes
NTP service: active
RTC in local TZ: no

# 查看详细信息
$ timedatectl –all
Local time: Thu 2026-04-03 10:40:15 CST
Universal time: Thu 2026-04-03 02:40:15 UTC
RTC time: Thu 2026-04-03 02:40:15
Time zone: Asia/Shanghai (CST, +0800)
System clock synchronized: yes
NTP service: active
RTC in local TZ: no

# 查看系统时间
$ date
Thu Apr 3 10:40:15 CST 2026

# 查看硬件时钟
$ sudo hwclock –show
2026-04-03 02:40:15.123456+00:00

# 列出所有时区
$ timedatectl list-timezones
Africa/Abidjan
Africa/Accra
Africa/Addis_Ababa
Africa/Algiers
Africa/Asmara
Africa/Bamako
Africa/Bangui
Africa/Banjul
Africa/Bissau
Africa/Blantyre
Africa/Brazzaville
Africa/Bujumbura
Africa/Cairo
Africa/Casablanca
Africa/Ceuta
Africa/Conakry
Africa/Dakar
Africa/Dar_es_Salaam
Africa/Djibouti
Africa/Douala
Africa/El_Aaiun
Africa/Freetown
Africa/Gaborone
Africa/Harare
Africa/Johannesburg
Africa/Juba
Africa/Kampala
Africa/Khartoum
Africa/Kigali
Africa/Kinshasa
Africa/Lagos
Africa/Libreville
Africa/Lome
Africa/Luanda
Africa/Lubumbashi
Africa/Lusaka
Africa/Malabo
Africa/Maputo
Africa/Maseru
Africa/Mbabane
Africa/Mogadishu
Africa/Monrovia
Africa/Nairobi
Africa/Ndjamena
Africa/Niamey
Africa/Nouakchott
Africa/Ouagadougou
Africa/Porto-Novo
Africa/Sao_Tome
Africa/Tripoli
Africa/Tunis
Africa/Windhoek
America/Adak
America/Anchorage
America/Anguilla
America/Antigua
America/Araguaina
…
Asia/Shanghai
Asia/Singapore
Asia/Srednekolymsk
Asia/Taipei
Asia/Tashkent
Asia/Tbilisi
Asia/Tehran
Asia/Thimphu
Asia/Tokyo
Asia/Tomsk
Asia/Ulaanbaatar
Asia/Urumqi
Asia/Ust-Nera
Asia/Vientiane
Asia/Vladivostok
Asia/Yakutsk
Asia/Yangon
Asia/Yekaterinburg
Asia/Yerevan
…

# 搜索特定时区
$ timedatectl list-timezones | grep Shanghai
Asia/Shanghai

$ timedatectl list-timezones | grep US
America/Adak
America/Anchorage
America/Boise
America/Chicago
America/Denver
America/Detroit
America/Indiana/Indianapolis
America/Indiana/Knox
America/Indiana/Marengo
America/Indiana/Petersburg
America/Indiana/Tell_City
America/Indiana/Vevay
America/Indiana/Vincennes
America/Indiana/Winamac
America/Kentucky/Louisville
America/Kentucky/Monticello
America/Los_Angeles
America/Menominee
America/Metlakatla
America/New_York
America/Nome
America/North_Dakota/Beulah
America/North_Dakota/Center
America/North_Dakota/New_Salem
America/Phoenix
America/Sitka
America/Yakutat
Pacific/Honolulu

# 修改时区为上海时间
$ sudo timedatectl set-timezone Asia/Shanghai

# 验证时区修改
$ timedatectl
Local time: Thu 2026-04-03 10:45:00 CST
Universal time: Thu 2026-04-03 02:45:00 UTC
RTC time: Thu 2026-04-03 02:45:00
Time zone: Asia/Shanghai (CST, +0800)
System clock synchronized: yes
NTP service: active
RTC in local TZ: no

# 修改时区为纽约时间
$ sudo timedatectl set-timezone America/New_York

# 验证时区修改
$ timedatectl
Local time: Wed 2026-04-02 22:45:00 EDT
Universal time: Thu 2026-04-03 02:45:00 UTC
RTC time: Thu 2026-04-03 02:45:00
Time zone: America/New_York (EDT, -0400)
System clock synchronized: yes
NTP service: active
RTC in local TZ: no

# 恢复为上海时间
$ sudo timedatectl set-timezone Asia/Shanghai

# 查看当前时间
$ date
Thu Apr 3 10:50:00 CST 2026

# 手动设置系统时间（需要先关闭NTP同步）
$ sudo timedatectl set-ntp false

# 设置系统时间为2026年4月3日 11:00:00
$ sudo timedatectl set-time “2026-04-03 11:00:00”

# 验证时间设置
$ date
Thu Apr 3 11:00:00 CST 2026

# 只设置日期
$ sudo timedatectl set-time “2026-04-04”

# 验证日期设置
$ date
Fri Apr 4 11:00:00 CST 2026

# 只设置时间
$ sudo timedatectl set-time “12:00:00”

# 验证时间设置
$ date
Fri Apr 4 12:00:00 CST 2026

# 恢复正确日期
$ sudo timedatectl set-time “2026-04-03 12:00:00”

# 重新启用NTP同步
$ sudo timedatectl set-ntp true

# 查看NTP同步状态
$ timedatectl
System clock synchronized: yes
NTP service: active

# 禁用NTP同步
$ sudo timedatectl set-ntp false

# 验证NTP已禁用
$ timedatectl
System clock synchronized: no
NTP service: inactive

# 启用NTP同步
$ sudo timedatectl set-ntp true

# 验证NTP已启用
$ timedatectl
System clock synchronized: yes
NTP service: active

# 查看NTP同步状态
$ systemctl status chronyd
● chronyd.service – NTP client/server
Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled; preset: enabled)
Active: active (running) since Thu 2026-04-03 10:35:20 CST; 1h 30min ago
Docs: man:chronyd(8)
man:chrony.conf(5)
https://chrony.tuxfamily.org/documentation.html
Main PID: 12345 (chronyd)
Tasks: 2 (limit: 49152)
Memory: 1.2M
CPU: 125ms
CGroup: /system.slice/chronyd.service
└─12345 /usr/sbin/chronyd

# 查看RTC配置
$ timedatectl
RTC in local TZ: no

# 设置RTC使用本地时区
$ sudo timedatectl set-local-rtc true

# 验证RTC配置
$ timedatectl
RTC in local TZ: yes

# 查看硬件时钟
$ sudo hwclock –show
2026-04-03 12:00:00.更多视频教程www.fgedu.net.cn123456+08:00

# 恢复RTC使用UTC
$ sudo timedatectl set-local-rtc false

# 验证RTC配置
$ timedatectl
RTC in local TZ: no

# 查看硬件时钟
$ sudo hwclock –show
2026-04-03 04:00:00.123456+00:00

# 场景：系统时间不同步
# 1. 检查时间同步状态
$ timedatectl
System cl更多学习教程公众号风哥教程itpux_comock synchronized: no
NTP service: inactive

# 2. 启用NTP服务
$ sudo timedatectl set-ntp true

# 3. 检查chronyd服务状态
$ sudo systemctl status chronyd
● chronyd.service – NTP client/server
Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled; preset: enabled)
Active: inactive (dead)

# 4. 启动chronyd服务
$ sudo systemctl start chronyd

# 5. 验证服务状态
$ sudo systemctl status chronyd
● chronyd.service – NTP client/server
Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled; preset: enabled)
Active: active (running) since Thu 2026-04-03 12:05:00 CST; 5s ago

# 6. 检查时间同步状态
$ timedatectl
System clock synchronized: yes
NTP service: active

# 7. 查看同步源
$ chronyc sources
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
^* ntp.aliyun.com 2 6 377 25 -234us[ -567us] +/- 10ms