A wristwatch (an example of a timepiece) includes a small dial (an example of a dial) and a rotary disk (an example of a rotary member). The small dial includes a sun mark for displaying the state of the sun. The rotary disk covers the small dial and rotates in a 24-hour period. The rotary disk includes the sun state indicator that changes the visibility of the sun mark in accordance with the rotational position of the rotary disk. One of the small dial and the rotary member includes a plurality of numbers (an example of indexes) for indicating time. The other of the small dial and the rotary member includes a time indicator that indicates a number in accordance with the rotational position of the rotary disk. The time indicator and the sun state indicator are disposed relative to each other in a positional relationship such that the visibility of the sun mark by the sun state indicator corresponds to the state of the sun corresponding to the number indicated by the time indicator.

A device for selection of a combination of motifs for a timepiece, including an inner disc, and a coaxial outer disc, the inner disc having a smaller diameter than the outer disc, the discs including angular sectors of the same size, at least two angular sectors of each disc bearing a motif on their periphery; a device for actuation permitting rotation of the inner disc, and a gear device for coupling the two discs according to a reduction ratio; a dial extending opposite the inner disc, the dial including an aperture to put a motif of the inner disc and a motif of the outer disc into correspondence, such that a complete rotation of the inner disc gives rise to a rotation of the outer disc by one angular sector, the size of the aperture being sufficiently large for each motif of the outer disc to be in correspondence successively with all the motifs of the inner disc, when the inner disc is rotated.

A timepiece including at least analogue time display device, and an AM-PM display device for displaying day-night information in the dial of the timepiece. The AM-PM display device includes at least two apertures made in the dial of the watch, a rotating display disc bearing at least one first series of inscriptions corresponding to the day and at least one second series of inscriptions corresponding to the night, these two display series being disposed on at least two concentric circles, and a drive mechanism arranged so as to automatically and alternately bring the first series of inscriptions inside a first aperture and the second series of inscriptions inside a second aperture by rotating the display disc.

An analogue information display system for a watch provided with a mechanical movement includes a display dial including a plurality of apertures, a moving display part supporting graphical representations, disposed in such a way that the graphical representations supported thereby appear in the plurality of apertures in order to generate the information, and an indicator member configured so as to designate a piece of information generated in an aperture to be notified to the wearer of the watch.

A watch includes a timepiece movement including a mechanism for displaying a time period or season which includes a first wheel which is provided in order to turn once in thirty-one days for displaying a day of the month, and a second wheel for displaying another time period or season. The second wheel turns more quickly than the first wheel for displaying this time period or season, and the second wheel is provided in order to be displaced from the first wheel, at the rate of one turn in a period of time between 340 days and 380 days.

A lunar phase display device including an annular cover including four ring portions, two successive ring portions being separated by a convex lobe projecting radially towards the inside of the annular cover; a moon indicator disc, a drive device arranged to move the moon indicator disc so that the disc makes a cycloidal trajectory between two successive lobes, the moon indicator disc being at least partially occulted by each of the two lobes during one portion of the cycloidal trajectory so as to reproduce the phases of the moon during a lunar month.

An adjustable timer teaches time in a simple manner to those having difficulty understanding the concept of time. The timer displays remaining and elapsed time. The timer may be set to rotate a shaft at different speeds. A colored disk is attached to the shaft. Boards having faces with different numerical indicia reside in a cavity and may be interchanged by a user. The exposed board face corresponds to the setting of the timer such that one full rotation of the shaft and disk corresponds to the numerical indicia of the exposed board face.

A moon phase indicator mechanism, for a timepiece provided with a movement and a dial, the moon phase indicator mechanism including at least one moon disc, and at least one moon phase train driven by the timepiece movement, the moon phase train meshing with a moon phase wheel which carries the moon disc at least indirectly and in a fixed manner, the moon phase wheel taking the form of a toothed ring in order to move the moon disc with the moon phase train about an axis A.

An adjustable timer teaches time in a simple manner to those having difficulty understanding the concept of time. The timer displays remaining and elapsed time. The timer may be set to rotate a shaft at different speeds. A colored disk is attached to the shaft. Boards having faces with different numerical indicia reside in a cavity and may be interchanged by a user. The exposed board face corresponds to the setting of the timer such that one full rotation of the shaft and disk corresponds to the numerical indicia of the exposed board face.

A device for selection of a combination of motifs for a timepiece, including an inner disc, and a coaxial outer disc, the inner disc having a smaller diameter than the outer disc, the discs including angular sectors of the same size, at least two angular sectors of each disc bearing a motif on their periphery; a device for actuation permitting rotation of the inner disc, and a gear device for coupling the two discs according to a reduction ratio; a dial extending opposite the inner disc, the dial including an aperture to put a motif of the inner disc and a motif of the outer disc into correspondence, such that a complete rotation of the inner disc gives rise to a rotation of the outer disc by one angular sector, the size of the aperture being sufficiently large for each motif of the outer disc to be in correspondence successively with all the motifs of the inner disc, when the inner disc is rotated.