Timepiece with a mobile display

An electronic timepiece providing at least one information from the group of information consisting of the passage of a time interval T and the approach of an event E in relation to the functions or the operation of said timepiece, comprising:

• a time-keeping circuit having an oscillator delivering a base time signal S.sub.0, and a division chain receiving the signal S.sub.0 and delivering time signals S.sub.1, S.sub.2, S.sub.3,
• a dial for displaying said items of information,
• exterior command members delivering at least a function signal S'
• a mobile display, occupying at least a part of the dial and adapted to display said at least one information, said mobile display comprising an assembly of n discrete elements P.sub.j forming puzzle on a rear part of which a design is disposed,
• a command circuit for controlling said mobile display by selectively activating said elements P.sub.j, said command circuit being responsive to at least one of a group of signals consisting of said time signals and said function signal S' for controlling the rhythm of increase or decrease of the number x of said elements P.sub.j that are activated and effecting, at each variation in the number of elements activated, a random or pseudo random selection of which of said elements amongst the n elements of said puzzle are activated, a portion of said design revealed to view being progressively varied during the passage of a time interval T, and/or the approach of an event E in relation to the functions or the operation of said timepiece.