Timepiece calendar system

1. A timepiece calendar system comprising:

a date indication mobile;

a first indexing device for indexing the position of the date indication mobile, wherein, when the first indexing device is activated, the position of the date indication mobile is indexed by the first indexing device in each of at least two different positions indicating two successive calendar days, wherein the first indexing device comprises a first toothset having successive teeth cooperating with a first head to index the date indication mobile on successive calendar days;

a second indexing device for indexing the position of the date indication mobile, wherein, when the second indexing device is activated, the position of the date indication mobile is indexed by successive teeth of the second indexing device in at least two different positions indicating two successive calendar days, wherein the second indexing device comprises a second toothset having successive teeth cooperating with a second head to index the date indication mobile on successive calendar days, the second toothset being separate from the first toothset;

an activating and deactivating element for activating and deactivating at least one of the first and second indexing devices, wherein each the first and second indexing devices is activated and deactivated by activating and deactivating the cooperation of the respective first or second toothset and the respective first or second head to index the date indication mobile on successive calendar days,

wherein the second indexing device is deactivated whenever the first indexing device is activated and the first indexing device is deactivated whenever the second indexing device is activated, so that the indexing of the date indication mobile by one or the other of the first and second indexing devices is mutually exclusive.

2. The system as claimed in claim 1 , wherein the activation and deactivation element comprises:

a first deactivation device for deactivating the first indexing device; and

a second activation device for activating the second indexing device,

the first deactivation device being so that the first indexing device is deactivated and the second activating device being so that the second indexing device is activated when the date indication mobile is driven on passing from a short month to the next month.

3. The system as claimed in claim 2 , wherein the first deactivation device and the second deactivation device are arranged so that (i) the first indexing device is deactivated and the second indexing device is activated during at least one day preceding the passage from any short month having less than 31 days to the next month, and (ii) the first indexing device is activated and the second indexing device is deactivated by default during all days of any long month and during all days of any short month other than the at least one day preceding the passage from the short month to the next month.

4. The system as claimed in claim 3 , comprising an element for driving the date indication mobile, the first indexing device being so that the date indication mobile is moved one step on each action of the drive element and the second indexing device being so that the date indication mobile is moved by two steps on each action of the drive element occurring at the end of the thirtieth day of a short month.

5. The system as claimed in claim 2 , comprising a drive element for driving the date indication mobile, the first indexing device being so that the date indication mobile is moved one step on each action of the drive element and the second indexing device being so that the date indication mobile is moved by two steps on each action of the drive element occurring at the end of the thirtieth day of a short month.

6. The system as claimed in claim 2 , wherein at least one selected from the group consisting of (i) the first deactivation device for deactivating the first indexing device includes a control cam, and (ii) the second activation device for activating the second indexing device includes a control cam.

7. The system as claimed in claim 6 , wherein the second activation device for activating the second indexing device includes a control cam, and the second indexing device is adapted to cooperate with the control cam.

8. The system as claimed in claim 2 , wherein the first deactivation device for deactivating the first indexing device includes a first banking on the first indexing device cooperating with a second banking on the second indexing device so as to move the first indexing device away from a first position cooperating with the date indication mobile and to subject the second indexing device to a torque of a first return spring of the first indexing device when the second indexing device is cooperating with the date indication mobile.

9. The system as claimed in claim 2 , wherein the first deactivation device is arranged so that the first indexing device is deactivated and the second activation device is arranged so that the second indexing device is activated during two days preceding the passage from a short month to the next month.

10. The system as claimed in claim 1 , wherein the first indexing device includes a jumper and a first return spring.

11. The system as claimed in claim 10 , wherein the jumper is adapted to cooperate with a first toothset of the date indication mobile because of the effect of the first return spring.

12. The system as claimed in claim 11 , wherein the second indexing device includes a lever having a head, and a second return spring, wherein the lever is adapted to cooperate with a second toothset of the date indication mobile because of the effect of at least one selected from the group consisting of the first return spring and the second return spring.

13. The system as claimed in claim 12 , wherein the second toothset has a cam surface enabling a roller to drive the date indication mobile over two steps of the date indication mobile.

14. The system as claimed in claim 1 , wherein the second indexing device includes a lever having a head, and a second return spring.

15. The system as claimed in claim 1 , wherein the first and second indexing devices are rotatable about the same axis and a return torque on the second indexing device about the axis is less than a return torque on the first indexing device about the axis.

16. The system as claimed in claim 1 , wherein the system is of the instantaneous jump type.

17. A timepiece movement including a system as claimed in claim 1 .

18. A timepiece including a system as claimed in claim 1 .

19. The timepiece calendar system as claimed in claim 1 ,

wherein the first indexing device comprises a jumper ca ring the first head acting on the first toothset of the date indication mobile under the effect of a first spring to index the date indication mobile;

wherein the second indexing device comprises a lever carrying the second head acting on the second toothset of the date indication mobile under the effect of a second spring to index the date indication mobile; and

wherein the lever of the second indexing device is deactivated by inhibiting the action of the second head of the lever whenever the jumper of the first indexing device is activated and the jumper of the first indexing device is deactivated k inhibiting the action of the first head of the jumper whenever the second jumper of the second indexing device is activated, so that the indexing of the date indication mobile by one or the other of the first and second indexing devices is mutually exclusive.

20. A method of operating a timepiece calendar system comprising:

a date indication mobile;

a first indexing device for indexing the position of the date indication mobile, wherein, when the first indexing device is activated, the position of the date indication mobile is indexed by the first indexing device in at least two different positions indicating two successive calendar days, wherein the first indexing device comprises a first toothset having successive teeth cooperating with a first head to index the date indication mobile on successive calendar days;

the second indexing device for indexing the position of the date indication mobile, wherein, when the second indexing device is activated, the position of the date indication mobile is indexed by the second indexing device in at least two different positions indicating two successive calendar days, wherein the second indexing device comprises a second toothset having successive teeth cooperating with a second head to index the date indication mobile on successive calendar days, the second toothset being separate from the first toothset;

an activation and deactivation element for activating and deactivating at least one of the first and second indexing devices, wherein each the first and second indexing devices is activated and deactivated by activating and deactivating the cooperation of the respective first or second toothset and the respective first or second head to index the date indication mobile on successive calendar days,

the method including:

deactivating the first indexing device and activating the second indexing device for the passage from dates of a short month to the next month.

21. The method of claim 20 , wherein the method includes keeping the first indexing device active and keeping the second indexing device inactive for the passage from dates of a long month to the next month.

22. The method as claimed in claim 20 , comprising (i) deactivating the first indexing device and activating the second indexing device during at least one day preceding the passage from any short month having less than 31 days to the next month, wherein (ii) the first indexing device is activated and the second indexing device is deactivated by default during all days of any long month and during all days of any short month other than the at least one day preceding the passage from the short month to the next month.

23. The method as claimed in claim 20 , comprising driving the date indication mobile by one step when the first indexing device is activated and driving the date indication mobile by two steps at least once when the second indexing device is activated.

24. The method as claimed in claim 20 , wherein the timepiece calendar system has a configuration wherein the second indexing device is deactivated whenever the first indexing device is activated and the first indexing device is deactivated whenever the second indexing device is activated, so that the indexing of the date indication mobile by one or the other of the first and second indexing devices is mutually exclusive.

25. The method as claimed in claim 20 ,

wherein the first indexing device comprises a jumper carrying the first head acting on the first toothset of the date indication mobile under the effect of a first spring to index the date indication mobile;

wherein the second indexing device comprises a lever carrying the second head acting on the second toothset of the date indication mobile under the effect of a second spring to index the date indication mobile; and

wherein the lever of the second indexing device is deactivated by inhibiting the action of the second head of the lever whenever the jumper of the first indexing device is activated and the jumper of the first indexing device is deactivated k inhibiting the action of the first head of the jumper whenever the second jumper of the second indexing device is activated, so that the indexing of the date indication mobile by one or the other of the first and second indexing devices is mutually exclusive.