Here's the guide on setting up automatic restarts with warning messages on DayZ server:

1. Open the Game Panel Scheduled Tasks.
2. Create a New Scheduled Task.
3. From the drop-down menu, choose Console/RCON Command and click on the New link.
4. On the next page, enter the following details:
   RCon Password: <YOUR RCON PASSWORD>
   Command to Execute: say -1 Server is restarting in 60 minutes
   Name: Choose a preferred name for this task
   Enabled: Check the box
   Type: Daily
   Start: Set it to your preference
   Recur every: 1 day
   Repeat Task: Check the box
   Repeat every: 4 hours
   For: 24 hours
   
   It should look like this:
   
5. To find the Rcon password, refer to the DZserver.cfg and your active BattlEye config. Remember, the Rcon password must match both cfg files.
6. The "Repeat every 4 hours" means that the task will repeat every 4 hours for a total of 24 hours.
7. Remember to create multiple tasks for other warning messages, such as a 30-minute warning, 15-minute warning, etc.
8. For the Restart task, select the "Scheduled Start/Stop/Restart" task type from the drop-down menu.

If you have any questions, feel free to reach out to us.