Instantaneous calendar device for timepieces

An instantaneous calendar device for time pieces having a hour wheel and a 24-hour wheel in mesh with each other and an intermediate gear mounted coaxially with said 24-hour wheel, comprising a date ring with a toothed rim;

• a day disk;
• a driven disk mounted on the intermediate gear and having a projection interacting with teeth of said date ring to rotate said date ring;
• a seven-position Maltese means rigidly coupled to, and coaxially mounted with, said day disk, locking surfaces of the Maltese means interacting with a side surface of said driven disk;
• a pin for transferring said Maltese means mounted on the periphery of said intermediate gear;
• and a locking means having a thrust arm interacting with teeth of said date ring and a lever arm interacting with said locking arcs of said Maltese means.