diff --git a/src/util/time-unit-test-clock.cpp b/src/util/time-unit-test-clock.cpp
new file mode 100644
index 0000000..73c30f7
--- /dev/null
+++ b/src/util/time-unit-test-clock.cpp
@@ -0,0 +1,82 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2014 Regents of the University of California.
+ *
+ * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
+ *
+ * ndn-cxx library is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-cxx library is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.
+ *
+ * You should have received copies of the GNU General Public License and GNU Lesser
+ * General Public License along with ndn-cxx, e.g., in COPYING.md file.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
+ */
+
+#include "time-unit-test-clock.hpp"
+
+namespace ndn {
+namespace time {
+
+template<class BaseClock>
+UnitTestClock<BaseClock>::UnitTestClock(const nanoseconds& startTime)
+  : m_currentTime(startTime)
+{
+}
+
+template<class BaseClock>
+std::string
+UnitTestClock<BaseClock>::getSince() const
+{
+  return " since unit test clock advancements";
+}
+
+template<class BaseClock>
+typename BaseClock::time_point
+UnitTestClock<BaseClock>::getNow() const
+{
+  return typename BaseClock::time_point(duration_cast<typename BaseClock::duration>(m_currentTime));
+}
+
+template<class BaseClock>
+boost::posix_time::time_duration
+UnitTestClock<BaseClock>::toPosixDuration(const typename BaseClock::duration& duration) const
+{
+  return
+#ifdef BOOST_DATE_TIME_HAS_NANOSECONDS
+    boost::posix_time::nanoseconds(1)
+#else
+    boost::posix_time::microseconds(1)
+#endif
+    ;
+}
+
+
+template<class BaseClock>
+void
+UnitTestClock<BaseClock>::advance(const nanoseconds& duration)
+{
+  m_currentTime += duration;
+}
+
+template<class BaseClock>
+void
+UnitTestClock<BaseClock>::setNow(const nanoseconds& timeSinceEpoch)
+{
+  m_currentTime = timeSinceEpoch;
+}
+
+template
+class UnitTestClock<system_clock>;
+
+template
+class UnitTestClock<steady_clock>;
+
+} // namespace time
+} // namespace ndn