We do not have enough data on this route to provide a reliable graph showing how many days before departure it is the best to book.
However, usually the closer it is to the departure, the more expensive the tickets are.
The most popular airlines on the route San Francisco (CA) - Switzerland: Turkish Airlines (TK), British Airways (BA), Icelandair (FI).
There is no direct flight on the route from San Francisco (CA) to Switzerland
Il volo con scalo più breve dura 32h 5min.