A position sensor and method for determining an axial and/or an angular position of a setting stem of a timepiece. A magnet is provided on the setting stem, and at least one magnetic field sensor is configured to detect changes in magnetic field strength along at least a first axis and a second axis as the rotatable element rotates; the second axis is not parallel to the first axis. The changing magnetic field sensed by the magnetic sensor is converted into a characteristic signature path which may then be mapped onto a circular signature path in two dimensions to derive the angular position of the setting stem.