updated readme.

README.MD

@@ -75,3 +75,34 @@ Todo
 
 Todo
 
+### etc/systemd/system/make-backup.service  
+Systemd service to make backup.  
+WorkingDirectory should be the absolute path to where make_backup.sh script is located.
+ExecStart *MUST* be the absolute path to make_backup.sh
+
+### etc/systemd/system/make-backup.timer  
+Systemd timer to trigger backup.  
+When backups are made is defined in the line:    
+```OnCalendar=Mon-Sun *-*-* 04:00:00```  
+See ```man systemd.time``` for more how to configure OnCalendar events.
+
+### Systemd service+timer install  
+Configure the trigger in the .timer, remember to change "Description" in both .service and .timer. 
+```systemd-analyze verify make-backup.*```  
+Have systemd verify that the files are correct before continueing.  
+If there is any errors, FIX THOSE FIRST!  
+ 
+```cp make-backup.* /etc/systemd/system/.```  
+Copy the files to /etc/systemd/system.
+
+```systemctl daemon-reload```  
+Have systemd track the files you just added.
+
+```systemctl start make-backup.service```
+Trigger the backup via systemd to verify that everything is working as expected.
+
+```systemctl enable make-backup.timer --now```
+If the .service works and makes backups as wanted you can now enable the .timer.
+
+DONE!!
+