This display shows the twelve months of the year.

The twelve months are sometimes shown on a circle with a hand in the center pointing to the month. They can also sometimes appear on an arc of a circle with a retrograde display.

The months can also be inscribed on a disc, part of which will appear through a dial aperture. These months can sometimes also be printed in the language of the market where the watches will be sold.

With some perpetual calendars of the first hour we have not 12 months on 360 degrees but 48 months on 360 degrees, corresponding to the three years and the leap year. These two devices can also be marked under a dial either with a twelve star or a 48 star.