diff --git a/include/boost/date_time/posix_time/date_duration_operators.hpp b/include/boost/date_time/posix_time/date_duration_operators.hpp
new file mode 100644
index 0000000..159971d
--- /dev/null
+++ b/include/boost/date_time/posix_time/date_duration_operators.hpp
@@ -0,0 +1,60 @@
+#ifndef DATE_DURATION_OPERATORS_HPP___
+#define DATE_DURATION_OPERATORS_HPP___
+                                                                                
+/* Copyright (c) 2004 CrystalClear Software, Inc.
+ * Subject to the Boost Software License, Version 1.0. 
+ * (See accompanying file LICENSE-1.0 or 
+ * http://www.boost.org/LICENSE-1.0)
+ * Author: Jeff Garland, Bart Garst
+ * $Date$
+ */
+
+#include "boost/date_time/gregorian/greg_duration_types.hpp"
+#include "boost/date_time/posix_time/ptime.hpp"
+
+namespace boost {
+namespace posix_time {
+
+  /*** ptime operator functions ***/
+  // ptime & months
+  ptime operator+(const ptime& t, const boost::gregorian::months& m)
+  {
+    return t + m.get_offset(t.date());
+  }
+  ptime operator+=(ptime& t, const boost::gregorian::months& m)
+  {
+    // get_neg_offset returns a negative duration, so we add
+    return t += m.get_offset(t.date());
+  }
+  ptime operator-(const ptime& t, const boost::gregorian::months& m)
+  {
+    // get_neg_offset returns a negative duration, so we add
+    return t + m.get_neg_offset(t.date());
+  }
+  ptime operator-=(ptime& t, const boost::gregorian::months& m)
+  {
+    return t += m.get_neg_offset(t.date());
+  }
+  // ptime & years
+  ptime operator+(const ptime& t, const boost::gregorian::years& y)
+  {
+    return t + y.get_offset(t.date());
+  }
+  ptime operator+=(ptime& t, const boost::gregorian::years& y)
+  {
+    return t += y.get_offset(t.date());
+  }
+  ptime operator-(const ptime& t, const boost::gregorian::years& y)
+  {
+    // get_neg_offset returns a negative duration, so we add
+    return t + y.get_neg_offset(t.date());
+  }
+  ptime operator-=(ptime& t, const boost::gregorian::years& y)
+  {
+    // get_neg_offset returns a negative duration, so we add
+    return t += y.get_neg_offset(t.date());
+  }
+
+}} // namespaces
+
+#endif // DATE_DURATION_OPERATORS_HPP___
diff --git a/include/boost/date_time/posix_time/posix_time.hpp b/include/boost/date_time/posix_time/posix_time.hpp
index aafa03d..292bc25 100644
--- a/include/boost/date_time/posix_time/posix_time.hpp
+++ b/include/boost/date_time/posix_time/posix_time.hpp
@@ -13,6 +13,9 @@
 
 #include "boost/date_time/compiler_config.hpp"
 #include "boost/date_time/posix_time/ptime.hpp"
+#if defined(BOOST_DATE_TIME_OPTIONAL_GREGORIAN_TYPES)
+#include "boost/date_time/posix_time/date_duration_operators.hpp"
+#endif
 #if defined(BOOST_DATE_TIME_NO_WSTRING_CONVERSIONS)
 #include "boost/date_time/posix_time/time_formatters_limited.hpp"
 #else
diff --git a/include/boost/date_time/posix_time/posix_time_types.hpp b/include/boost/date_time/posix_time/posix_time_types.hpp
index 0c28906..a603b1f 100644
--- a/include/boost/date_time/posix_time/posix_time_types.hpp
+++ b/include/boost/date_time/posix_time/posix_time_types.hpp
@@ -10,6 +10,9 @@
 #include "boost/date_time/time_clock.hpp"
 #include "boost/date_time/microsec_time_clock.hpp"
 #include "boost/date_time/posix_time/ptime.hpp"
+#if defined(BOOST_DATE_TIME_OPTIONAL_GREGORIAN_TYPES)
+#include "boost/date_time/posix_time/date_duration_operators.hpp"
+#endif
 #include "boost/date_time/posix_time/posix_time_duration.hpp"
 #include "boost/date_time/posix_time/posix_time_system.hpp"
 #include "boost/date_time/posix_time/time_period.hpp"