rename todatetime to totimedelta on Duration.

added some tests for the same function
closes #4

2 files changed, 15 insertions, 1 deletions

diff --git a/src/isodate/duration.py b/src/isodate/duration.py
index 0d5e0fa..12c0df4 100644
--- a/src/isodate/duration.py
+++ b/src/isodate/duration.py
@@ -251,7 +251,7 @@ class Duration(object):
             return True
         return False
 
-    def todatetime(self, start=None, end=None):
+    def totimedelta(self, start=None, end=None):
         '''
         Convert this duration into a timedelta object.
 
diff --git a/src/isodate/tests/test_duration.py b/src/isodate/tests/test_duration.py
index a66652e..7d72704 100644
--- a/src/isodate/tests/test_duration.py
+++ b/src/isodate/tests/test_duration.py
@@ -323,6 +323,20 @@ class DurationTest(unittest.TestCase):
         #        treats a != b the same b != a
         #self.assertNotEqual(timedelta(days=1), Duration(days=1))
 
+    def test_totimedelta(self):
+        '''
+        Test conversion form Duration to timedelta.
+        '''
+        dur = Duration(years=1, months=2, days=10)
+        self.assertEqual(dur.totimedelta(datetime(1998, 2, 25)), timedelta(434))
+        # leap year has one day more in february
+        self.assertEqual(dur.totimedelta(datetime(2000, 2, 25)), timedelta(435))        
+        dur = Duration(months=2)
+        # march is longer than february, but april is shorter than march (cause only one day difference compared to 2)
+        self.assertEqual(dur.totimedelta(datetime(2000, 2, 25)), timedelta(60))        
+        self.assertEqual(dur.totimedelta(datetime(2001, 2, 25)), timedelta(59))        
+        self.assertEqual(dur.totimedelta(datetime(2001, 3, 25)), timedelta(61))        
+
 
 def create_parsetestcase(durationstring, expectation, format, altstr):
     """