The image below is an example of a date control on a web application that describes how it works:
1. View the Calendar:
Depending on the type of selected calendar (See 7.1.2.7.3), by selecting this button, the calendar form opens to select the date.
2. Year and Month Previous and Next:
By selecting these buttons you can see the calendar year before and after, and the calendar of the month before and next.
If user clicks on Month, then all months in the Year are displayed
If user clicks onto the year, the set of 10 current years are displayed
The next click shows the set of decades in the century.