Retrieves the minimum size required to display a full month in a month calendar control. You can send this message explicitly or by using the MonthCal_GetMinReqRect macro.


Must be zero.

Pointer to a RECT structure that will receive bounding rectangle information. This parameter must be a valid address and cannot be NULL.

Return value

Returns nonzero and lParam receives the applicable bounding information if successful. Otherwise, the message returns zero.


The minimum required window size for a month calendar control depends on the currently selected font, control styles, system metrics, and regional settings. When an application changes anything that affects the minimum window size, or processes a WM_SETTINGCHANGE message, it should send MCM_GETMINREQRECT to determine the new minimum size.

Note   The rectangle returned by MCM_GETMINREQRECT does not include the width of the "Today" string, if it is present. If the MCS_NOTODAY style is not set, your application should also retrieve the rectangle that defines the "Today" string width by sending a MCM_GETMAXTODAYWIDTH message. Use the larger of the two rectangles to ensure that the "Today" string is not clipped.

The top and left members of the structure pointed to by lParam will always be zero. The right and bottom members represent the minimum cx and cy required for the control.


Minimum supported client

Windows Vista [desktop apps only]

Minimum supported server

Windows Server 2003 [desktop apps only]