Merge remote-tracking branch 'leo-naeka/master'

src/icalendar/prop.py

@@ -433,8 +433,9 @@ class vDDDTypes:
             tzinfo = dt.tzinfo
             if tzinfo is not pytz.utc and not isinstance(tzinfo, tzutc):
                 # set the timezone as a parameter to the property
-                tzid = dt.tzinfo.zone
-                self.params.update({'TZID': tzid})
+                tzid = tzinfo_from_dt(dt)
+                if tzid:
+                    self.params.update({'TZID': tzid})
         self.dt = dt
 
     def to_ical(self):

src/icalendar/tests/test_timezoned.py

@@ -109,8 +109,12 @@ class TestTimezoned(unittest.TestCase):
         # references: #73,7430b66862346fe3a6a100ab25e35a8711446717 
 
         date = dateutil.parser.parse('2012-08-30T22:41:00Z')
+        date2 = dateutil.parser.parse('2012-08-30T22:41:00 +02:00')
         self.assertTrue(date.tzinfo.__module__ == 'dateutil.tz')
+        self.assertTrue(date2.tzinfo.__module__ == 'dateutil.tz')
 
         # make sure, it's parsed properly and doesn't throw an error
         self.assertTrue(icalendar.vDDDTypes(date).to_ical()
                         == '20120830T224100Z')
+        self.assertTrue(icalendar.vDDDTypes(date2).to_ical()
+                        == '20120830T224100')