To make this answer a useful one, a minimal example for a daily automatic scheduled script at 01:30.
- Create two files, one service file and one timer file. Both names (.timer and .service) have to match. F.e.:
sudo vim /usr/lib/systemd/system/scheduledScript.service
sudo vim /usr/lib/systemd/system/scheduledScript.timer
(The folder /usr/lib/systemd/system/... is the default folder containing all .service files)