Device for providing an electro-optical display of time

A device for providing an electro-optical display of time comprises an electronic timekeeper fed by a voltage source and including a time base and a frequency divider. An electro-optical display is formed of groups of electro-chromic cells each able to take two different visual aspects. The cells are controlled by a code converter supplying state variables corresponding to the desired aspects of the cells to provide a display of time. One aspect of the cells corresponds to a stable state, the other aspect to a quasi-stable state which in order to be maintained, requires very low or zero power. Transition of a cell from one state to another requires precisely determined amounts of energy. A change detector supplies to a selector, data to actuate the operations of inscription and erasure of the display cells. The selector dispenses the required amounts of energy supplied to the display to ensure correspondence between the state variables delivered by the code converter and the aspect of the corresponding display cells, in a manner ensuring transition from one state to another with a minimum supply of energy.