Porsche Cayman Owner's Manual page 120

Resetting the time
After timing has been stopped, the on-board
computer display changes to the "Continue/Reset"
selection.
Select "Reset" with the operating lever.
118
Controls, Instruments
Push operating lever forward. The display
returns to the "Start timing" selection. The
stopwatch displays in the instrument panel and
the on-board computer are reset to zero.