According to Google Maps, a walk around Lake Zurich takes between 18 and 21 hours, depending on the route. Time enough to think about one or more special things and relax. The photos here are not made in the same day, I am not so fast.
The most beautiful city on Lake Zurich is not Zurich, but is located at the other end and is Rapperswil, there is much more lake as a result of the semi-island location.
Have agreat Day!