Hi Christian,
In the BIOS on bootes, there is an option to control the RTC alarm via the operating system. In fact, it is the default. I wonder if it might make sense to instead call rtcwake [1] to shut the system down and check back in a few hours.
Argo and Lyra are Dell Poweredge 4130 systems and they do not seem to have any option in their BIOS to configure an RTC alarm. However, I had success shutting down Lyra for ten minutes with:
sudo rtcwake -m off -s 600
I only tried a dry run (with "-n -v" suffixed to the command), but:
sudo rtcwake -m off --date +6hour
appears to work as expected. I could make use of the existing
system by setting up a service that called rtcwake at boot to set
up an alarm and refresh it on a timer at regular intervals, but it
seems like it would be simpler to integrate the wakeup into your
system by calling `rtcwake -m off` instead of `shutdown`.
Sincerely,
Cory Bloor
[1]: https://manpages.debian.org/testing/util-linux/rtcwake.8.en.html