Index: trunk/FACT++/src/makeplots.cc
===================================================================
--- trunk/FACT++/src/makeplots.cc	(revision 15177)
+++ trunk/FACT++/src/makeplots.cc	(revision 15178)
@@ -145,5 +145,5 @@
 
     const double jd  = floor(time.Mjd())+2400001;
-    const double mjd = floor(time.Mjd())+49718+0.5;
+    const double mjd = floor(time.Mjd())+49718+0.5; // root time
 
     cout << "Time: " << time     << endl;
@@ -178,4 +178,7 @@
     // ------------- Create canvases and frames ---------------------
 
+    // It is important to use an offset which is larger than
+    // 1970-01-01 00:00:00. This one will not work if your
+    // local time zone is positive!
     TH1S hframe("", "", 1, (mjd+jd0)*24*3600, (mjd+jd1)*24*3600);
     hframe.SetStats(kFALSE);