diff --git a/tests/unit-tests/interval.t.cpp b/tests/unit-tests/interval.t.cpp
new file mode 100644
index 0000000..e9cf6d9
--- /dev/null
+++ b/tests/unit-tests/interval.t.cpp
@@ -0,0 +1,155 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2015,  Regents of the University of California
+ *
+ * This file is part of ndn-group-encrypt (Group-based Encryption Protocol for NDN).
+ * See AUTHORS.md for complete list of ndn-group-encrypt authors and contributors.
+ *
+ * ndn-group-encrypt is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-group-encrypt 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * ndn-group-encrypt, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author Zhiyi Zhang <dreamerbarrychang@gmail.com>
+ */
+
+#include "interval.hpp"
+#include "boost-test.hpp"
+
+namespace ndn {
+namespace gep {
+namespace tests {
+
+using namespace boost::posix_time;
+
+BOOST_AUTO_TEST_SUITE(TestInterval)
+
+BOOST_AUTO_TEST_CASE(Construction)
+{
+  // construct with the right parameters
+  Interval interval1(from_iso_string("20150825T120000"),
+                     from_iso_string("20150825T160000"));
+  BOOST_CHECK_EQUAL(to_iso_string(interval1.getStartTime()), "20150825T120000");
+  BOOST_CHECK_EQUAL(to_iso_string(interval1.getEndTime()), "20150825T160000");
+  BOOST_CHECK_EQUAL(interval1.isValid(), true);
+
+  // construct with the invalid interval
+  Interval interval2;
+  BOOST_CHECK_EQUAL(interval2.isValid(), false);
+
+  // construct with the empty interval
+  Interval interval3(true);
+  BOOST_CHECK_EQUAL(interval3.isValid(), true);
+  BOOST_CHECK_EQUAL(interval3.isEmpty(), true);
+}
+
+BOOST_AUTO_TEST_CASE(CoverTimePoint)
+{
+  Interval interval(from_iso_string("20150825T120000"),
+                    from_iso_string("20150825T160000"));
+
+  TimeStamp tp1 = from_iso_string("20150825T120000");
+  TimeStamp tp2 = from_iso_string("20150825T130000");
+  TimeStamp tp3 = from_iso_string("20150825T170000");
+  TimeStamp tp4 = from_iso_string("20150825T110000");
+
+  BOOST_CHECK_EQUAL(interval.covers(tp1), true);
+  BOOST_CHECK_EQUAL(interval.covers(tp2), true);
+  BOOST_CHECK_EQUAL(interval.covers(tp3), false);
+  BOOST_CHECK_EQUAL(interval.covers(tp4), false);
+}
+
+BOOST_AUTO_TEST_CASE(IntersectionAndUnion)
+{
+  Interval interval1(from_iso_string("20150825T030000"),
+                     from_iso_string("20150825T050000"));
+  // no intersection
+  Interval interval2(from_iso_string("20150825T050000"),
+                     from_iso_string("20150825T070000"));
+  // no intersection
+  Interval interval3(from_iso_string("20150825T060000"),
+                     from_iso_string("20150825T070000"));
+  // there's an intersection
+  Interval interval4(from_iso_string("20150825T010000"),
+                     from_iso_string("20150825T040000"));
+  // right in the interval1, there's an intersection
+  Interval interval5(from_iso_string("20150825T030000"),
+                     from_iso_string("20150825T040000"));
+  // wrap the interval1, there's an intersection
+  Interval interval6(from_iso_string("20150825T010000"),
+                     from_iso_string("20150825T050000"));
+  // empty interval
+  Interval interval7(true);
+
+  Interval tempInterval = interval1;
+  tempInterval && interval2;
+  BOOST_CHECK_EQUAL(tempInterval.isEmpty(), true);
+
+  tempInterval = interval1;
+  BOOST_CHECK_THROW(tempInterval || interval2, Interval::Error);
+
+  tempInterval = interval1;
+  tempInterval && interval3;
+  BOOST_CHECK_EQUAL(tempInterval.isEmpty(), true);
+
+  tempInterval = interval1;
+  BOOST_CHECK_THROW(tempInterval || interval3, Interval::Error);
+
+  tempInterval = interval1;
+  tempInterval && interval4;
+  BOOST_CHECK_EQUAL(tempInterval.isEmpty(), false);
+  BOOST_CHECK_EQUAL(to_iso_string(tempInterval.getStartTime()), "20150825T030000");
+  BOOST_CHECK_EQUAL(to_iso_string(tempInterval.getEndTime()), "20150825T040000");
+
+  tempInterval = interval1;
+  tempInterval || interval4;
+  BOOST_CHECK_EQUAL(tempInterval.isEmpty(), false);
+  BOOST_CHECK_EQUAL(to_iso_string(tempInterval.getStartTime()), "20150825T010000");
+  BOOST_CHECK_EQUAL(to_iso_string(tempInterval.getEndTime()), "20150825T050000");
+
+  tempInterval = interval1;
+  tempInterval && interval5;
+  BOOST_CHECK_EQUAL(tempInterval.isEmpty(), false);
+  BOOST_CHECK_EQUAL(to_iso_string(tempInterval.getStartTime()), "20150825T030000");
+  BOOST_CHECK_EQUAL(to_iso_string(tempInterval.getEndTime()), "20150825T040000");
+
+  tempInterval = interval1;
+  tempInterval || interval5;
+  BOOST_CHECK_EQUAL(tempInterval.isEmpty(), false);
+  BOOST_CHECK_EQUAL(to_iso_string(tempInterval.getStartTime()), "20150825T030000");
+  BOOST_CHECK_EQUAL(to_iso_string(tempInterval.getEndTime()), "20150825T050000");
+
+  tempInterval = interval1;
+  tempInterval && interval6;
+  BOOST_CHECK_EQUAL(tempInterval.isEmpty(), false);
+  BOOST_CHECK_EQUAL(to_iso_string(tempInterval.getStartTime()), "20150825T030000");
+  BOOST_CHECK_EQUAL(to_iso_string(tempInterval.getEndTime()), "20150825T050000");
+
+  tempInterval = interval1;
+  tempInterval || interval6;
+  BOOST_CHECK_EQUAL(tempInterval.isEmpty(), false);
+  BOOST_CHECK_EQUAL(to_iso_string(tempInterval.getStartTime()), "20150825T010000");
+  BOOST_CHECK_EQUAL(to_iso_string(tempInterval.getEndTime()), "20150825T050000");
+
+  tempInterval = interval1;
+  tempInterval && interval7;
+  BOOST_CHECK_EQUAL(tempInterval.isEmpty(), true);
+
+  tempInterval = interval1;
+  tempInterval || interval7;
+  BOOST_CHECK_EQUAL(tempInterval.isEmpty(), false);
+  BOOST_CHECK_EQUAL(to_iso_string(tempInterval.getStartTime()), "20150825T030000");
+  BOOST_CHECK_EQUAL(to_iso_string(tempInterval.getEndTime()), "20150825T050000");
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+} // namespace tests
+} // namespace gep
+} // namespace ndn