diff --git a/libs/temporal/test/BBTTest.cc b/libs/temporal/test/BBTTest.cc
index fc287db11c..ac4db926e1 100644
--- a/libs/temporal/test/BBTTest.cc
+++ b/libs/temporal/test/BBTTest.cc
@@ -150,4 +150,47 @@ BBTTest::deltaTest ()
 	o = m.bbt_delta (b, a);
 
 	CPPUNIT_ASSERT_EQUAL (BBT_Offset (0, 10, 841), o);
+
+	a = BBT_Time (1, 1, 0);
+	b = BBT_Time (10, 1, 0);
+	o = m.bbt_delta (b, a);
+
+	CPPUNIT_ASSERT_EQUAL (BBT_Offset (9, 0, 0), o);
+
+	a = BBT_Time (1, 12, 0);
+	b = BBT_Time (10, 1, 0);
+	o = m.bbt_delta (b, a);
+
+	CPPUNIT_ASSERT_EQUAL (BBT_Offset (8, 1, 0), o);
+
+	a = BBT_Time (1, 1, 0);
+	b = BBT_Time (1, 1, 1);
+	o = m.bbt_delta (b, a);
+
+	CPPUNIT_ASSERT_EQUAL (BBT_Offset (0, 0, 1), o);
+
+	a = BBT_Time (1, 1, 960);
+	b = BBT_Time (1, 2, 0);
+	o = m.bbt_delta (b, a);
+
+	CPPUNIT_ASSERT_EQUAL (BBT_Offset (0, 0, 0), o);
+
+	a = BBT_Time (1, 1, 959);
+	b = BBT_Time (1, 2, 0);
+	o = m.bbt_delta (b, a);
+
+	CPPUNIT_ASSERT_EQUAL (BBT_Offset (0, 0, 1), o);
+
+
+	a = BBT_Time (1, 1, 480);
+	b = BBT_Time (1, 2, 959);
+	o = m.bbt_delta (b, a);
+
+	CPPUNIT_ASSERT_EQUAL (BBT_Offset (0, 1, 479), o);
+
+	a = BBT_Time (1, 1, 480);
+	b = BBT_Time (1, 1, 959);
+	o = m.bbt_delta (b, a);
+
+	CPPUNIT_ASSERT_EQUAL (BBT_Offset (0, 0, 479), o);
 }