diff --git a/include/wx/datetime.h b/include/wx/datetime.h
index f6bb9cdc29..5b6804709a 100644
--- a/include/wx/datetime.h
+++ b/include/wx/datetime.h
@@ -1781,9 +1781,16 @@ inline wxDateTime wxDateTime::Today()
 #if (!(defined(__VISAGECPP__) && __IBMCPP__ >= 400))
 inline wxDateTime& wxDateTime::Set(time_t timet)
 {
-    // assign first to avoid long multiplication overflow!
-    m_time = timet - WX_TIME_BASE_OFFSET ;
-    m_time *= TIME_T_FACTOR;
+    if ( timet == (time_t)-1 )
+    {
+        m_time = wxInvalidDateTime.m_time;
+    }
+    else
+    {
+        // assign first to avoid long multiplication overflow!
+        m_time = timet - WX_TIME_BASE_OFFSET;
+        m_time *= TIME_T_FACTOR;
+    }
 
     return *this;
 }
diff --git a/interface/wx/datetime.h b/interface/wx/datetime.h
index 01ef279dcf..9c07d391d6 100644
--- a/interface/wx/datetime.h
+++ b/interface/wx/datetime.h
@@ -483,6 +483,9 @@ public:
     /**
         Constructs the object from @a timet value holding the number of seconds
         since Jan 1, 1970.
+
+        If @a timet is invalid, i.e. @code (time_t)-1 @endcode, wxDateTime
+        becomes invalid too, i.e. its IsValid() will return @false.
     */
     wxDateTime& Set(time_t timet);
     /**