Abstract: An electronic wristwatch having a digital display and time-keeping apparatus for driving said digital display is provided with calculating means selectively coupled to said digital display. An input arrangement for said calculating means is provided consisting of a ring rotatably mounted on said wristwatch, and fixed and rotatable contact means respectively mounted on said wristwatch and ring for selective alignment at positions representative of the numerals 0 to 9 and at least one function character. Switch means is provided for applying the numerical or function character at which said ring is set to said calculating means, a further switch means being provided for selective setting of the wristwatch between a time keeping and calculating mode.