diff --git a/src/tools.cpp b/src/tools.cpp
index 6b2013c..a43ef55 100644
--- a/src/tools.cpp
+++ b/src/tools.cpp
@@ -629,6 +629,8 @@ namespace xmreg
         return make_pair(empty_time, scale);
     }
 
+    // useful reference to get epoch time in correct timezon
+    // http://www.boost.org/doc/libs/1_41_0/doc/html/date_time/examples.html#date_time.examples.seconds_since_epoch
     time_t
     ptime_to_time_t(const pt::ptime& in_ptime)
     {
diff --git a/src/tools.h b/src/tools.h
index 569c336..ed2151a 100644
--- a/src/tools.h
+++ b/src/tools.h
@@ -43,7 +43,7 @@ namespace xmreg
     namespace bf = boost::filesystem;
     namespace pt = boost::posix_time;
     namespace gt = boost::gregorian;
-
+    namespace lt = boost::local_time;
 
 
     struct outputs_visitor