Index: /trunk/FACT++/src/DataProcessorImp.cc
===================================================================
--- /trunk/FACT++/src/DataProcessorImp.cc	(revision 11998)
+++ /trunk/FACT++/src/DataProcessorImp.cc	(revision 11999)
@@ -27,5 +27,8 @@
 
     const Time time;
-    name << time.GetAsStr("%Y/%m/%d/");
+
+    const Time night = time - boost::posix_time::hours(12);
+
+    name << night.GetAsStr("%Y/%m/%d/");
 
     try