Dual display timepiece

A mechanism for the additional secondary display of a first physical quantity, which includes a first push-button arranged for activating control means of first means for coupling/uncoupling said secondary display to or from a movement including a first display, wherein said secondary display includes a pivoting first physical quantity cannon-pinion heart, the coupling/uncoupling means of which is arranged for controlling the coupling/uncoupling to or from said movement, a second zero reset push-button for said secondary display for resetting said secondary display to zero by uncoupling said coupling/uncoupling means, and by returning said cannon-pinion heart to the original position thereof, wherein it includes second coupling/uncoupling control means, which includes either a pivoting time zone wheel set, including a friction wheel meshing with said movement and a time zone wheel, which, when said time zone wheel set is in the coupling position, directly or indirectly drives a second physical quantity cannon-pinion heart, and/or a third physical quantity cannon-pinion heart, said friction wheel and time zone wheel being coaxial and able to cooperate with each other via a friction coupling;

• or an inter-time zone mechanism, carried by a control lever comprised in said control means of the first coupling/uncoupling means, said inter-time zone mechanism being a coupling mechanism and including a bottom wheel directly meshing with said movement, and a top wheel, which, when said inter-time zone mechanism is in the coupling position, is arranged for directly or indirectly driving at least said second physical quantity cannon-pinion heart, and/or said third physical quantity cannon-pinion heart.