afx_msg void OnTimeChange();
Called after the system time is changed.
Have any application that changes the system time send this message to all top-level windows. To send the WM_TIMECHANGE message to all top-level windows, an application can use the SendMessage Windows function with the hWnd parameter set to 0xFFFF.
This message-handler member function calls the Default member function. Override this member function in your derived class to handle the WM_TIMECHANGE message.
::SendMessage, CWnd::Default, WM_TIMECHANGE