A timepiece includes: a movement (10) that has a balance wheel/spring assembly (12) having a system for adjusting the operative length of the spring, which is rotatable; a control member (14) that is accessible, by the user, outside the timepiece; a transmission wheel (22) that is rotatably mounted, on the periphery of the movement (10), onto a frame, the movement (10) being placed inside the transmission wheel, the transmission wheel (22) being kinematically connected or connectable to the control member (14) and moreover being kinematically connected to the adjustment system; and a display part (30) that is kinematically connected to the transmission wheel (22) and drives a display member, intended for displaying the adjustment value that is applied to the operative length of the spring. The display part (30) is formed of movable parts that are mounted onto a first separate module, assembled to the frame.