I am running a dedicated Minecraft server, and I want it to restart every night at midnight. I'm running it in a screen session so I can easily access it. However, if I just run screen -X -S server quit, it does not save the world. I will use cron to restart it every night.
Seems to make sense to backup the world before shutting down the screen session.
I would think this would help: http://www.scaine.net/site/2013/08/backing-up-your-minecraft-server-in-ubuntu%EF%BB%BF%EF%BB%BF/
or this: https://forum.feed-the-beast.com/threads/minecraft-custom-linux-backups-using-crontab-and-screen.45575/
Filing this under "Who Knew?" on Stack Exchange we have a sister-site called Arcade where your question has an answer:
On our sister-site Unix & Linux there is this answer:
This will probably suit your needs better.