The switching mechanism for setting the time in an electronic wrist watch comprises a switch blade actuated by a double-lobe cam which is connected by a lost-motion coupling with a coaxial transmission wheel having at its periphery gear teeth meshing with a winding pinion on a round part of the winding stem which is perpendicular to the axis of the transmission wheel and cam. The winding pinion and a clutch wheel which is rotatable with the winding stem have rectangular teeth which are engageable with each other to connect the winding pinion with the winding stem. A protuberance of a cam spring is engageable with one lobe of the cam to restrain rotation of the cam until the lost-motion coupling reaches the end of its travel. The construction permits its use in a thin watch.