Timepiece enabling the hours of one half of a day to be differentiated from those of the other half of the day

A timepiece comprising a movement, a dial, indicator means that are rotatably driven about an axis by said movement at the rate of one revolution every twelve hours and which cooperate with said dial to indicate during a first revolution the hours of a first half of a day and during a second revolution consecutive to the first revolution the hours of the second half of the day, and means for differentiating the hours of a first half of a day from the hours of the second half of the day and which include a first transparent region in said dial in a first angular position corresponding to the angular position occupied by said indicator means at a first set hour during said first half of a day and at a second set hour distant from said one set hour by a time interval of twelve hours, an element rotatable about said axis and disposed beneath said dial, a first group of signs disposed on said rotatable element facing said dial the same distance away from said axis as said first transparent region and which include a first sign representing the number of said first set hour and a second sign different from said first sign and representing the number of said second set hour, and means for driving said rotatable element that are connected to said movement and which are arranged to move said rotatable element at a first instant at the start of said first half of a day into a first position in which said first sign faces said first transparent region and at a second instant at the start of said second half of a day into a second position in which said second sign faces said first transparent region, and to maintain said rotatable element in said first position during said first half of a day and in said second position during said second half of the day, wherein the drive means are so arranged that said rotatable element will always rotate in the same direction.