timedatectl: Check Linux Server Time Sync Status and Set the Time Zone

Test environmentRHEL familyAlmaLinux 9.8systemd 252 · chrony 4.8root accountDebian 12 regular accountChecked 2026-10-29

System info · settings commandstimedatectlLocation/usr/bin/timedatectl

timedatectl is a systemd command that checks and changes the system clock, time zone, and NTP time synchronization status of a Linux server. When the time sync status was checked on an AlmaLinux 9 server that uses chrony and a Debian 12 server that uses ntpsec, both servers had their clocks synchronized, but the NTP service line showed active on one and n/a on the other.

The outputs below are results from running the commands on the two servers. Only host names, IP addresses, and package version numbers were replaced with example values, and commands that change the time or time zone were not run on the production server.

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4mn read

1️⃣ timedatectl Usage and Checking the Linux Server Time

Running timedatectl without options gives the same result as adding status. The time of the system clock and the hardware clock (RTC), the time zone, and the sync status are gathered on one screen. Below is the result on the Debian 12 server.

timedatectl

               Local time: Wed 2026-10-28 19:49:57 UTC
           Universal time: Wed 2026-10-28 19:49:57 UTC
                 RTC time: Wed 2026-10-28 19:49:57
                Time zone: Etc/UTC (UTC, +0000)
System clock synchronized: yes
              NTP service: n/a
          RTC in local TZ: no

The Debian 12 server's time zone is Etc/UTC, so Local time and Universal time showed the same time. What each line tells you and the results from the two servers are in the table below.

Output line	What it shows	Results from the two servers and what to check
Local time	Current time of the system clock with the time zone applied	Changing the time zone changes only this line and the date output to the new zone
Universal time	The same time expressed in UTC	Stays the same when the time zone changes — on the Debian 12 server (Etc/UTC) it equals Local time
RTC time	Time of the hardware clock (RTC)	Shown without a time zone — UTC time when RTC in local TZ is no
Time zone	Configured time zone, its abbreviation, and offset from UTC	Use a name from the list-timezones list when changing it
System clock synchronized	Whether the kernel considers the clock synchronized	yes on both servers — if no, check the reference server first with chronyc tracking or ntpq -p
NTP service	Whether the sync service that timedatectl turns on and off is running	active on AlmaLinux 9 (chrony), n/a on Debian 12 (ntpsec) — n/a means the service is unknown to timedatectl, so check it with systemctl
RTC in local TZ	Whether the hardware clock is kept in local time (no = UTC)	no on both servers — the command to switch yes to UTC is set-local-rtc 0

Linux has two clocks. The system clock is kept by the kernel after boot, and the hardware clock is the motherboard clock that keeps time even while the server is powered off.

Read the hardware clock directly with hwclock. hwclock prints the time converted to the current time zone. On the AlmaLinux server, reading it with TZ=UTC in front of the command returned a UTC time ending in +00:00.

TZ=UTC hwclock --show

2026-10-28 19:53:33.006788+00:00

On the Debian 12 server, accessed with a regular user account, the same command ended without being able to access the hardware clock.

/usr/sbin/hwclock --show

hwclock: Cannot access the Hardware Clock via any known method.
hwclock: Use the --verbose option to see the details of our search for an access method.

The RTC in local TZ line is the same setting as the third line of the /etc/adjtime file. On the AlmaLinux server the third line was UTC, which means the hardware clock is kept in UTC.

cat /etc/adjtime

0.0 0 0.0
0
UTC

Use show instead of status when reading values in a script. On the Debian 12 server, it prints the same information as name=value, one per line.

timedatectl show

Timezone=Etc/UTC
LocalRTC=no
CanNTP=no
NTP=no
NTPSynchronized=yes
TimeUSec=Wed 2026-10-28 19:49:57 UTC
RTCTimeUSec=Wed 2026-10-28 19:49:57 UTC

Pick properties with -p and add --value to keep only the values without names. Use this form to pull out just the time zone name.

timedatectl show -p Timezone --value

Etc/UTC

🔲 timedatectl Command Simulator

In the simulator below, you can type commands to check the time, list time zones, change the time zone, and check sync with chronyc.

timedatectl Command Simulatorsystemd 252 · chrony 4.8

[root@server work]#

Runs only in your browser. A changed time zone goes back to the start (Etc/UTC) on reload, and ↑↓ recalls earlier commands.

2️⃣ Linux Server Time Synchronization Status

The System clock synchronized line shows whether the kernel considers the clock synchronized, and the NTP service line shows whether the sync service that timedatectl can turn on and off is running. With show, the same values appear as NTPSynchronized and NTP, and CanNTP shows whether there is a sync service that can be turned on and off.

On the AlmaLinux 9 server using chrony, all three values were yes.

timedatectl show -p CanNTP -p NTP -p NTPSynchronized

CanNTP=yes
NTP=yes
NTPSynchronized=yes

On the Debian 12 server, which keeps time with ntpsec, only NTPSynchronized was yes, and CanNTP and NTP were no. That is why the NTP service line showed n/a on this server's status screen.

timedatectl show -p CanNTP -p NTP -p NTPSynchronized

CanNTP=no
NTP=no
NTPSynchronized=yes

The ntpsec service itself was running.

systemctl is-active ntpsec

active

The only sync services timedatectl knows are those listed in the list files in the ntp-units.d folder, and distribution packages put these files in /usr/lib/systemd/ntp-units.d/ (per the official manual). The AlmaLinux 9 server had a list file installed by the chrony package, containing a single line, chronyd.service.

cat /usr/lib/systemd/ntp-units.d/50-chronyd.list

chronyd.service

rpm -qf /usr/lib/systemd/ntp-units.d/50-chronyd.list

chrony-4.8-10.el9.x86_64

The Debian 12 server did not have this folder. Since ntpsec is not in the list, timedatectl knew the clock was synchronized but could not turn that service on or off.

ls /usr/lib/systemd/ntp-units.d/

ls: cannot access '/usr/lib/systemd/ntp-units.d/': No such file or directory

🖥️ timedatectlstatus, show, set-ntp

ntp-units.d/*.listList of sync services timedatectl turns on and off

chronyd.serviceIn the list → NTP service: active

ntpsec.serviceNot in the list → NTP service: n/a

3️⃣ Checking Time Sync with chronyc

On a server using chrony, check which time server the clock follows with chronyc. sources prints the time servers chronyd is querying and their state, one per line.

chronyc sources

MS Name/IP address         Stratum Poll Reach LastRx Last sample               
===============================================================================
^- 192.0.2.10                    2  10   377   943   +272us[ +275us] +/-   55ms
^- ntp1.example.com              2  10   377    80    -28us[  -32us] +/- 3655us
^- 198.51.100.33                 3  10   257   384   -151us[ -156us] +/-   97ms
^- 198.51.100.82                 3  10   177   532   +157us[ +149us] +/-   45ms
^* 192.0.2.123                   3   4   377     2    -21us[  -23us] +/-  312us

The leading ^ marks a time server, a * as the second character marks the reference server the clock currently follows, and - marks a candidate not combined in the calculation. Poll 4 on the reference server means it is queried every 16 seconds (2 to the 4th power), and Reach 377 means all of the last eight responses were received.

tracking prints how far the system clock is off from the reference server's time.

chronyc tracking

Reference ID    : C000027B (192.0.2.123)
Stratum         : 4
Ref time (UTC)  : Wed Oct 28 19:50:21 2026
System time     : 0.000002422 seconds slow of NTP time
Last offset     : -0.000002098 seconds
RMS offset      : 0.000000981 seconds
Frequency       : 6.348 ppm slow
Residual freq   : -0.001 ppm
Skew            : 0.017 ppm
Root delay      : 0.000300815 seconds
Root dispersion : 0.000150780 seconds
Update interval : 16.3 seconds
Leap status     : Normal

The System time line shows the system clock was 0.000002422 seconds behind NTP time, and Leap status was Normal. An Update interval of 16.3 seconds is the interval between the last two clock updates.

Which servers are queried is set by the pool and server lines in /etc/chrony.conf. Leaving only the setting lines, without comments and blank lines, gives the following.

grep -v "^#" /etc/chrony.conf | grep -v "^$"

pool 2.almalinux.pool.ntp.org iburst
sourcedir /run/chrony-dhcp
driftfile /var/lib/chrony/drift
makestep 1.0 3
rtcsync
keyfile /etc/chrony.keys
ntsdumpdir /var/lib/chrony
leapsectz right/UTC
logdir /var/log/chrony
server 192.0.2.123 prefer iburst minpoll 4 maxpoll 4

The pool line queries the AlmaLinux NTP pool, and prefer on the last server line is an option that makes chronyd pick this server before the others. makestep 1.0 3 is a setting that, for the first three updates after chronyd starts, corrects a clock off by more than 1 second in one step, and after that adjusts the clock gradually by running it slightly faster or slower. rtcsync makes the kernel copy the system time to the hardware clock every 11 minutes (per the official documentation).

On the Debian 12 server using ntpsec, the same information was checked with ntpq -p. The leading * is the reference server, and all three servers were being queried every 1024 seconds.

ntpq -p

     remote           refid      st t when poll reach   delay   offset   jitter
===============================================================================
+203.0.113.43    198.51.100.28    2 u  835 1024  377 184.6893  -0.1018   1.4879
+203.0.113.44    198.51.100.27    2 u  547 1024  377 183.0827  -2.4227   4.0957
*ntp2.example.co 198.51.100.40    2 u  440 1024  377 177.4670  -0.5814   1.7070

4️⃣ Changing the Time Zone with timedatectl

Check time zone names with list-timezones. Most names are in Continent/City form, one per line, and both servers had 598.

timedatectl list-timezones | head -5

Africa/Abidjan
Africa/Accra
Africa/Addis_Ababa
Africa/Algiers
Africa/Asmara

timedatectl list-timezones | wc -l

The list is long, so filter it with grep when looking for a name.

timedatectl list-timezones | grep -i new_york

America/New_York

Change the time zone by giving a name from the list after set-timezone. This command replaces the /etc/localtime link with the new time zone file, so run it with sudo from a regular account.

sudo timedatectl set-timezone America/New_York

Check with ls -l whether /etc/localtime is a link to a time zone file.

ls -l /etc/localtime

lrwxrwxrwx 1 root root 27 Sep 24 12:52 /etc/localtime -> /usr/share/zoneinfo/Etc/UTC

A name not in the list was rejected right away, before the time zone was changed.

timedatectl set-timezone Mars/Olympus

Failed to set time zone: Invalid or not installed time zone 'Mars/Olympus'

Changing the time zone leaves the system clock's time as it is, and only Local time and the output of the date command appear in the new zone. On a server that keeps the hardware clock in UTC, the hardware clock does not change either (per the official manual).

5️⃣ Turning On NTP and Setting the Time Manually with timedatectl

set-ntp true starts the first service in the sync service list and enables it at boot. false stops the services in the list and disables them at boot (per the official manual).

sudo timedatectl set-ntp true

On the Debian 12 server, which has no list file, the command ended with NTP not supported even when given false, the current value. A service not in the list, such as ntpsec, is started and stopped directly with systemctl.

timedatectl set-ntp false

Failed to set ntp: NTP not supported

To set the time manually, give the date and time after set-time. This command sets the hardware clock along with the system clock.

sudo timedatectl set-time '2026-10-28 20:00:00'

On the Debian 12 server, entering a value in the wrong format ended with an error without changing the time.

timedatectl set-time bad

Failed to parse time specification 'bad': Invalid argument

On a server using chrony, use chronyc makestep to correct a clock that is far off in one step.

sudo chronyc makestep

makestep drops the remaining difference that was being corrected gradually and makes the system clock jump by that amount at once. The official documentation warns that a sudden time change can affect some software, so use it only when the clock is too far off to correct slowly.

🔢 FAQ & Recommended Content

NTP services such as chrony and ntpsec keep the clock in sync, so there is rarely a reason to run rdate from cron. rdate was not installed on the AlmaLinux 9 server checked, and it was not in the list of installable packages either. The Debian 12 server's repository had an rdate 1.11 package, but it was not installed.

timesync-status is a command only for systemd-timesyncd. On both the AlmaLinux 9 server using chrony and the Debian 12 server using ntpsec, it ended with the Failed to query server error. On these servers, check the sync status with chronyc tracking or ntpq -p.

The official manual explains that keeping the hardware clock in local time can cause problems when the time zone changes or daylight saving time switches. It therefore recommends keeping it in UTC where possible, and the command to switch to UTC is sudo timedatectl set-local-rtc 0. Both servers checked were no (UTC).

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🪐ReferencesOfficial documentation

📡timedatectl(1) — systemd 252 manual (freedesktop.org) 📡chronyc command documentation — chrony 4.8 (chrony-project.org) 📡chrony.conf configuration documentation — chrony 4.8 (chrony-project.org)

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