diff --git a/test_ago.py b/test_ago.py
index 29ea8b2..c8dfac9 100644
--- a/test_ago.py
+++ b/test_ago.py
@@ -7,16 +7,22 @@ from types import DictType
 from ago import human
 from ago import delta2dict
 
+# datetime objects
 PRESENT = datetime.now()
 PAST    = PRESENT - timedelta( 492, 58711, 45 ) # days, secs, ms
 FUTURE  = PRESENT + timedelta( 2, 12447, 963 ) # days, secs, ms
 
+# timedelta objects
 PAST_DELTA   = PRESENT - PAST
 FUTURE_DELTA = PRESENT - FUTURE
+ONE_YEAR_FOUR_HOURS_DELTA = timedelta( 365, 14400, 0 )
 
-def test_human_is_string():
+def test_human_passed_datetime_is_string():
     assert type(human( PAST )) is StringType
 
+def test_human_passed_timedelta_is_string():
+    assert type(human( PAST_DELTA )) is StringType
+
 def test_delta2dict_is_dict():
     assert type(delta2dict( PAST_DELTA )) is DictType
 
@@ -34,6 +40,16 @@ def test_coma_in_three_precision():
     assert ',' in human( PAST, precision = 3 )
     assert ',' in human( FUTURE, precision = 3 )
 
+def test_coma_in_out_of_bounds_precision():
+    assert ',' in human( PAST, precision = 10 )
+    assert ',' in human( FUTURE, precision = 10 )
+
+def test_zero_day_is_skipped_display_hour():
+    _result = human( ONE_YEAR_FOUR_HOURS_DELTA, precision = 2 )
+    assert 'year' in _result
+    # day is 0 so it is skipped, so we should show hours ...
+    assert 'hour' in _result
+
 def test_one_day_singular():
     assert 's' not in human( timedelta(1) )
 
@@ -70,6 +86,7 @@ def test_valid_future_dict():
     assert past_dict['minute'] == 27
     assert past_dict['microsecond'] == 963
 
+
 def example_usage():
     """Test and example usage"""
 
@@ -78,9 +95,13 @@ def example_usage():
     print 'Commented ' + human( PAST_DELTA, 1 )
     print human( PAST, past_tense = "Commented {} ago" )
 
+    print human( ONE_YEAR_FOUR_HOURS_DELTA, past_tense = "Posted {} ago" )
+
     print '\nTest future tense:\n'
     print delta2dict( FUTURE_DELTA )
     print 'Shutdown ' + human( FUTURE_DELTA, 5 )
     print human( FUTURE, future_tense = 'Shutdown in {} from now' )
     print ''
 
+if __name__ == '__main__':
+    example_usage()