Patent ID: 8644116

Claim:
Calendar mechanism for a timepiece, comprising: at least one mobile ( 22 ; 23 ) for driving an indicator, a wheel ( 1 ) which, during normal operation of the timepiece, is driven in a first direction (S 1 ), and a lever ( 16 ) for actuating the mobile ( 22 ; 23 ), characterised in that it further comprises first and second cams ( 2 , 3 ) driven by the wheel ( 1 ) and controlling the movements of the actuating lever ( 16 ), these first and second cams ( 2 , 3 ) being arranged so that their relative angular position differs depending on the direction of rotation of the wheel ( 1 ) so that the movements of the actuating lever ( 16 ) cause the mobile ( 22 ; 23 ) to advance periodically during normal operation of the timepiece and do not permit the mobile ( 22 ; 23 ) to advance during backwards time setting of the timepiece causing the wheel ( 1 ) to rotate in a second direction (S 2 ) opposite to the first direction (S 1 ).