Date system for a horological movement comprising a tens disc (2) connected to a star wheel (4) driven by a first drive device (12), and a units disc (1) driven by a second drive device (13). The said drive devices (12, 13) are connected to a rocker (9) which works with cams (10, 11) connected to a driving runner (5), which effects one rotation per month. These cams (10, 11) are provided with a tooth (20) and a notch (21) which keep the first drive device (12) in the disengaged position until the tooth (20) and the notch (21) actuate the said rocker (9) in order to engage and disengage the respective drive devices (12, 13) in such a way as to move the display from the 31st to the 1st of the month without an error of one day between the date indicated and the actual date.