Edit:

I found a solution for me. I have generated a daily task with crontab (https://www.raspberrypi.org/documentation/linux/usage/cron.md), which restarts the MagicMirror with pm2 restart MagicMirror.sh every morning at 5 o’clock.

open crontab with crontab -e add 0 5 * * * pm2 restart MagicMirror.sh to the end off the file.