diff --git a/interface/wx/calctrl.h b/interface/wx/calctrl.h
index 40bd51493d..a756e458e3 100644
--- a/interface/wx/calctrl.h
+++ b/interface/wx/calctrl.h
@@ -469,7 +469,8 @@ public:
 
         The @a date parameter must be valid and in the currently valid range as
         set by SetDateRange(), otherwise the current date is not changed and
-        the function returns @false.
+        the function returns @false and, additionally, triggers an assertion
+        failure if the date is invalid.
     */
     virtual bool SetDate(const wxDateTime& date);
 
diff --git a/src/generic/calctrlg.cpp b/src/generic/calctrlg.cpp
index 58875a3066..3c5b8ce4e9 100644
--- a/src/generic/calctrlg.cpp
+++ b/src/generic/calctrlg.cpp
@@ -434,6 +434,8 @@ bool wxGenericCalendarCtrl::EnableMonthChange(bool enable)
 
 bool wxGenericCalendarCtrl::SetDate(const wxDateTime& date)
 {
+    wxCHECK_MSG( date.IsValid(), false, "invalid date" );
+
     bool retval = true;
 
     bool sameMonth = m_date.GetMonth() == date.GetMonth(),
diff --git a/src/gtk/calctrl.cpp b/src/gtk/calctrl.cpp
index 221fa53ef5..fbeb93edf8 100644
--- a/src/gtk/calctrl.cpp
+++ b/src/gtk/calctrl.cpp
@@ -198,7 +198,9 @@ bool wxGtkCalendarCtrl::EnableMonthChange(bool enable)
 
 bool wxGtkCalendarCtrl::SetDate(const wxDateTime& date)
 {
-    if ( date.IsValid() && !IsInValidRange(date) )
+    wxCHECK_MSG( date.IsValid(), false, "invalid date" );
+
+    if ( !IsInValidRange(date) )
         return false;
 
     g_signal_handlers_block_by_func(m_widget,