I have a server set to the UTC time zone. It is running near Sydney and reports are sent to east coast users every day at 4:30PM

When I add a cron job I have to convert from Australia/Sydney time and specify the runtime in UTC time. When daylight savings takes effect in the Australia/Sydney timezone I need to manually change the cronjob in October and April every year.

Display the current system timezone

timedatectl status

#output
               Local time: Tue 2025-10-14 11:11:55 UTC
           Universal time: Tue 2025-10-14 11:11:55 UTC
                 RTC time: Tue 2025-10-14 11:11:55
                Time zone: UTC (UTC, +0000)
System clock synchronized: yes
              NTP service: active
          RTC in local TZ: no

Testing the validity of the .service and .timer files

sudo systemd-analyze verify ~/.config/systemd/user/dailyreport.*

There should be no output for good format and errors for bad formatting

Testing the OnCalendar snippet for the .timer file

systemd-analyze calendar 'Mon..Fri *-*-* 16:30:00 Australia/Sydney'

Creating the SystemD Service and Timer Files

~/.config/systemd/user/dailyreport.service

[Unit]
Description=Send daily report

[Service]
Type=oneshot
ExecStart=/var/www/wms/bin/cake daily_report

~/.config/systemd/user/dailyreport.timer

[Unit]
Description=Run Send Daily Report

[Timer]
OnCalendar=Mon..Fri *-*-* 16:30:00 Australia/Sydney
Persistent=true
Unit=dailyreport.service

[Install]
WantedBy=timers.target

Linger is Required for a user systemd timer to work

You need to set Linger=yes so your systemd user timer will run when the user is not logged in.

If your timer fails to run when your user is not Logged in it could be because of Linger=no

If Linger=No and Persistent=true is set in the .timer unit the unit will run at the next login

Login as the same user you want to run the systemd timer as and issue the following to show the current Linger setting

loginctl show-user myuser

loginctl enable-linger myuser

Restart / reload systemctl to get the timer to run

systemctl --user daemon-reload
systemctl --user enable dailyreport.timer
systemctl --user start dailyreport.timer

View the current system timers and when they next will run

systemctl --user list-timers --all

You can see the dailyreport.timer will next run in 22h