X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/017dc06b502c041c112a3948e6c5f65000a86d94..51248412979029d94d11ea5dab9516831be94914:/src/msw/calctrl.cpp

diff --git a/src/msw/calctrl.cpp b/src/msw/calctrl.cpp
index 7d80380b93..6af1285b68 100644
--- a/src/msw/calctrl.cpp
+++ b/src/msw/calctrl.cpp
@@ -474,7 +474,9 @@ bool wxCalendarCtrl::MSWOnNotify(int idCtrl, WXLPARAM lParam, WXLPARAM *result)
                 wxDateTime startDate;
                 startDate.SetFromMSWSysDate(ds->stStart);
 
-                wxDateTime currentDate = m_date;
+                // Ensure we have a valid date to work with.
+                wxDateTime currentDate = m_date.IsValid() ? m_date : startDate;
+
                 // Set to the start of month for comparison with startDate to
                 // work correctly.
                 currentDate.SetDay(1);