diff --git a/libs/temporal/test/BBTTest.cc b/libs/temporal/test/BBTTest.cc
index 032e643ded..fc287db11c 100644
--- a/libs/temporal/test/BBTTest.cc
+++ b/libs/temporal/test/BBTTest.cc
@@ -119,3 +119,35 @@ void
 BBTTest::convertTest()
 {
 }
+
+void
+BBTTest::deltaTest ()
+{
+	Meter m (12, 8);
+	BBT_Time a (5,12,0);
+	BBT_Time b (5,12,480);
+	BBT_Offset o (m.bbt_delta (b, a));
+
+	CPPUNIT_ASSERT_EQUAL (BBT_Offset (0, 0, 480), o);
+
+	a = BBT_Time (5,11,959);
+	o = m.bbt_delta (b, a);
+
+	CPPUNIT_ASSERT_EQUAL (BBT_Offset (0, 0, 481), o);
+
+	a = BBT_Time (4,11,959);
+	o = m.bbt_delta (b, a);
+
+	CPPUNIT_ASSERT_EQUAL (BBT_Offset (1, 0, 481), o);
+
+	a = BBT_Time (4,6,959);
+	o = m.bbt_delta (b, a);
+
+	CPPUNIT_ASSERT_EQUAL (BBT_Offset (1, 5, 481), o);
+
+	a = BBT_Time (4,4,959);
+	b = BBT_Time (5,3,840);
+	o = m.bbt_delta (b, a);
+
+	CPPUNIT_ASSERT_EQUAL (BBT_Offset (0, 10, 841), o);
+}
diff --git a/libs/temporal/test/BBTTest.h b/libs/temporal/test/BBTTest.h
index 9437919be3..14845e7402 100644
--- a/libs/temporal/test/BBTTest.h
+++ b/libs/temporal/test/BBTTest.h
@@ -10,6 +10,7 @@ class BBTTest : public CppUnit::TestFixture
 	CPPUNIT_TEST(multiplyTest);
 	CPPUNIT_TEST(convertTest);
 	CPPUNIT_TEST(roundTest);
+	CPPUNIT_TEST(deltaTest);
 	CPPUNIT_TEST_SUITE_END();
 
 public:
@@ -19,4 +20,5 @@ public:
 	void multiplyTest();
 	void convertTest();
 	void roundTest();
+	void deltaTest();
 };