System Uptime

System Uptime generates when a system has rebooted. Reboots can occur for various reasons, primarily including the following:

Last

Check the last reboot or shutdown using the last command

last -x reboot

or

last -x shutdown

The -x option provides additional information such as system down entries

else

Check for scheduled cron jobs that may have caused a reboot

crontab -l

If finding difficulty understanding cron entries, Use this.

else

Automatic system updates can sometimes trigger a reboot. Check the configuration with:

grep Automatic-Reboot-Time /etc/apt/apt.conf.d/50unattended-upgrades

else

It's possible that a user, such as a POC or end-user, initiated the reboot. Check with:

last | grep boot

else

Check the system logs for any messages related to the reboot:

cat /var/log/syslog | grep boot

Or using journalctl

journalctl -b -1

Email the POC with screenshot. Ask if there was a scheduled activity that caused the reboot, or if they are aware of any other reason for it.