BCGSuite for MFC
BOOL CBCGPCalendar::IsMiltipleSelection ( ) const
inline

Tells whether the calendar control is working in multiple selection, or single selection mode.

This function returns TRUE, if the calendar is working in the multiple selection mode. This function returns FALSE, if the calendar is working in the single selection mode.

In the single selection mode the user is allowed to select only one date. In the multiple selection mode the user is allowed to select multiple dates either by clicking and dragging the mouse, or by holding the Ctrl key and clicking on discrete days, or by clicking on the week number (it allows to select the entire week).

You can select multiple days in the code using SelectDate().