This section discusses how to configure the systemd-timedated system service, which configures system clock and timezone.
If you cannot remember whether or not the hardware clock is set to
UTC, find out by running the
--localtime --show command. This will display what
the current time is according to the hardware clock. If this time
matches whatever your watch says, then the hardware clock is set to
local time. If the output from hwclock is not local time, chances
are it is set to UTC time. Verify this by adding or subtracting the
proper amount of hours for the timezone to the time shown by
hwclock. For example,
if you are currently in the MST timezone, which is also known as GMT
-0700, add seven hours to the local time.
/etc/adjtime, and depending on the
contents of the file, it sets the clock to either UTC or local time.
/etc/adjtime file with the
following contents if your hardware clock is set to local time:
cat > /etc/adjtime << "EOF"
0.0 0 0.0 0 LOCALEOF
/etc/adjtime isn't present at first
will assume that hardware clock is set to UTC and adjust the file
according to that.
You can also use the timedatectl utility to tell systemd-timedated if your hardware clock is set to UTC or local time:
timedatectl set-local-rtc 1
timedatectl can also be used to change system time and time zone.
To change your current system time, issue:
timedatectl set-time YYYY-MM-DD HH:MM:SS
Hardware clock will also be updated accordingly.
To change your current time zone, issue:
timedatectl set-timezone TIMEZONE
You can get list of available time zones by running:
Please note that timedatectl command can be used only on a system booted with systemd.
Starting with version 213, systemd ships a daemon called systemd-timesyncd which can be used to synchronize the system time with remote NTP servers.
The daemon is not intended as a replacement for the well established NTP daemon, but as a client only implementation of the SNTP protocol which can be used for less advanced tasks and on resource limited systems.
Starting with systemd version 216, the systemd-timesyncd daemon is enabled by default. If you want to disable it, issue the following command:
systemctl disable systemd-timesyncd
can be used to change the NTP servers that systemd-timesyncd synchronizes
Please note that when system clock is set to Local Time, systemd-timesyncd won't update hardware clock.