Index: trunk/MagicSoft/Mars/mbase/MTime.cc
===================================================================
--- trunk/MagicSoft/Mars/mbase/MTime.cc	(revision 8999)
+++ trunk/MagicSoft/Mars/mbase/MTime.cc	(revision 9012)
@@ -759,12 +759,18 @@
     time.tm_mon   = mon-1;
     time.tm_year  = y-1900;
-    time.tm_isdst = 0;
-
+    time.tm_isdst = -1;
+
+    // -1: If dst, isdst is set to 1 but hour is not changed
+    //  0: If dst, hour is changed
+
+    // Get old local
     const TString locale = setlocale(LC_TIME, 0);
 
+    // Set new local (e.g. Montag instead of Monday)
     setlocale(LC_TIME, loc);
 
     // recalculate tm_yday and tm_wday
-    mktime(&time);
+    if (mktime(&time)<0)
+        return "";
 
     char ret[128];