The calendar form is displayed when it is double-clicked on any cell on the worksheet.Months are listed in the combobox control according to the user's system language starting from the month on the userform caption .
The ControlTipText value of the clicked button on the userform is added to the active cell as a date.
A date picker is a control that lets users quickly enter dates in a Microsoft Office InfoPath form by clicking a small pop-up calendar. For example, you can use a date picker to collect birth dates from people on an insurance form. You can also use a date picker to display preset dates, such as the current date.