systemd-timedated.service

timedatectl [OPTIONS...] {COMMAND}

status
    Displays current time, date, timezone, and NTP status.

set-time TIME
    Sets the system time. TIME can be an absolute date+time or now.

set-timezone TIMEZONE
    Sets the system timezone. Use list-timezones to find valid timezones.

set-ntp BOOL
    Enables or disables NTP synchronization. BOOL can be yes or no.

set-local-rtc BOOL
    Configures whether the RTC is in local time or UTC. BOOL can be yes or no.

list-timezones
    Lists available timezones.

show
    Show properties of the timedated service

The systemd-timedated.service command provides a mechanism for managing the system's time, date, and timezone settings. It acts as a system service accessible via the timedatectl command-line tool. This service communicates with the kernel to set the system clock, both the hardware clock (RTC) and the system clock (software). It also handles Network Time Protocol (NTP) synchronization to automatically adjust the time and keep it accurate.

Beyond basic time setting, the service also manages timezone configuration, allowing the system to accurately reflect the local time for a given geographic location. This service is crucial for proper system operation, as many applications and processes rely on an accurate system time.

The systemd-timedated service helps prevent inconsistencies by providing a unified interface for all time and date operations.

The RTC (Real-Time Clock) is a hardware clock. The systemd-timedated can synchronize the system time and RTC using NTP or manual time setting. The behavior is affected by /etc/adjtime.

Timezone settings are stored in /etc/localtime, which is a symbolic link to a timezone file in /usr/share/zoneinfo/. Incorrect timezone settings can lead to application errors and incorrect log timestamps.

The systemd-timedated service was introduced as part of the systemd init system. It replaced older methods of time and date management with a more robust and unified approach. Before systemd, different distributions had varying ways of handling time synchronization and timezone configuration, leading to inconsistencies. systemd-timedated aimed to standardize this process across all systems using systemd. Since its introduction, it has become the standard way to manage time and date in most modern Linux distributions.

date(1), hwclock(8), systemd(1)