From Einhugur Software:
The DateControl is a REALbasic control plugin to create a Date-picker. The Control is displayed according to control panel date settings, or in exclusive mm.dd.yyyy, exclusive dd.mm.yyyy or exclusive SQL format mode. "NULL" dates or what some would call no selection is supported. The control uses Native Windows control on Windows systems and native Theme Rendering on MacOS X and Linux systems.
Did adjustment on macOS and Linux systems so that the ValueChanged event will not fire twice in some situations like when dropping down the drop down window and selecting a date when the Date had previously been unchecked with empty dates on. (On Windows systems this behaviour is controlled by the OS).