timedatectl

• 時刻設定コマンド

• CentOS 7 以降

• 現在のタイムゾーン表示

  # timedatectl status
        Local time: 月 2019-02-18 09:34:46 JST
    Universal time: 月 2019-02-18 00:34:46 UTC
          RTC time: 月 2019-02-18 00:34:46
         Time zone: Asia/Tokyo (JST, +0900)
       NTP enabled: yes
  NTP synchronized: yes
   RTC in local TZ: no
        DST active: n/a
  

  • NTP enabled
    • NTP 時刻同期化有効
  • NTP synchronized
    • NTP 時刻同期化済み

• Asia/Tokyo に合わせたい

  # timedatectl set-timezone Asia/Tokyo
  

• 現在のタイムゾーンリスト

  # timedatectl list-timezones
  

• RTC を OS の時刻に合わせる

  • 現状の確認

    # cat /etc/adjtime
    0.0 0 0.0
    0
    UTC
    

  • 変更

    # timedatectl set-local-rtc 1
    

  • 確認 1

    # cat /etc/adjtime
    0.0 0 0.0
    0
    LOCAL
    

  • 確認 2

    # timedatectl status
          Local time: 月 2019-02-18 09:38:07 JST
      Universal time: 月 2019-02-18 00:38:07 UTC
            RTC time: 月 2019-02-18 09:38:06
           Time zone: Asia/Tokyo (JST, +0900)
         NTP enabled: yes
    NTP synchronized: yes
     RTC in local TZ: yes
          DST active: n/a
    
    Warning: The system is configured to read the RTC time in the local time zone.
             This mode can not be fully supported. It will create various problems
             with time zone changes and daylight saving time adjustments. The RTC
             time is never updated, it relies on external facilities to maintain it.
             If at all possible, use RTC in UTC by calling
             'timedatectl set-local-rtc 0'.