Bug#1110145: systemd: Timer's elapse time is gradually drifting further into the future

[Luca Boccassi]

Control: tags -1 moreinfo

On Wed, 30 Jul 2025 19:15:13 +0200 loomylabs <universal.wombat at web.de>
wrote:
> Package: systemd
> Version: 252.38-1~deb12u1
> Severity: normal
> X-Debbugs-Cc: universal.wombat at web.de
> 
> Dear Maintainer,
> 
> I have a server configured to automatically suspend using "systemctl
suspend" after X minutes of inactivity on specific monitored ports.
When traffic is detected on those ports, the gateway wakes the server
via Wake-on-LAN.
> 
> I have a systemd timer set to reboot the server sometime between 4
and 5 a.m.
> 
> The timer looks like this:
> 
> [Unit]
> Description=Daily reboot
> 
> [Timer]
> OnCalendar=*-*-* 04:00:00
> RandomizedDelaySec=3600
> WakeSystem=true
> Unit=reboot.target
> 
> [Install]
> WantedBy=timers.target
> 
> Each time the server wakes from suspend, the elapsed time is
recalculated and shifts progressively further into the future,
significantly surpassing the 4 to 5 o'clock window.

Can you reproduce on testing or unstable?