It depends on the community you live in. In each community (Gemeinde in German) there's a
Kreiswacht, who's a local police officer. Make a request for a parking place for your given date; they're also responsible for parking fines

, should you need to approach someone over one.
It also depends if your space is in a white or blue zone. Eg, 2 reserved white zone spaces for one day (7am - 5pm) in Seefeld, Zurich, costs CHF97. (Not sure how they calculate such a number, but it's a deal).
During those times, the police will tow away anyone using your space uninvited, as there'll be signs in place. You're getting more than a simple reservation, they actually will look out for you