Update documentation

README.md

@@ -20,7 +20,32 @@ sudo systemctl disable --now nbmrec.timer
 sudo make uninstall
 ```
 
+## Configuration
 
+In [./usr/local/etc/nbmrec/nbmrec.conf], you can specify a start and end time:
+
+```text
+START_TIME=22:00
+END_TIME=06:00
+```
+
+If you change the start date, you should update the systemd timer `nbmrec.timer` accordingly:
+
+```text
+#/etc/systemd/system/nbmrec.timer
+[...]
+OnCalendar=*-*-* 22:00
+[...]
+```
+
+Do not forget to reload systemd daemon after that:
+```bash
+sudo systemctl daemon-reload
+```
+
+
+
+You can also speci
 
 ## Reference