I automated the tedious work to create systemd timers in an ansible role: https://yourlabs.io/oss/yourlabs.timer

As a result, I can execute it include it in another ansible role, or use bigsudo to apply it as a one-off command:

    bigsudo yourlabs.timer @somehost name=your-backup cmd=/your/backup.sh oncalendar='*-*-* 00:00:00 Europe/Paris'