fix: allows until to be defined as datetime with timezone. Shamelessly copied code from @mbafford: https://github.com/jazzband/icalevents/pull/109/files

icalevents/icalparser.py

@@ -340,7 +340,9 @@ def parse_events(
             # Deal with the fact that sometimes it's a list and
             # sometimes it's a singleton
             exlist = []
-            if isinstance(component["EXDATE"], list):
+            if isinstance(component["EXDATE"], vDDDLists):
+                exlist = component["EXDATE"].dts
+            elif isinstance(component["EXDATE"], list):
                 exlist = component["EXDATE"]
             else:
                 exlist.append(component["EXDATE"])
@@ -487,13 +489,29 @@ def parse_rrule(component):
 
     def conform_until(until, dtstart):
         if type(dtstart) is datetime:
-            return (
+            # If we have timezone defined adjust for daylight saving time
+            if type(until) is datetime:
+                until_offset = (
+                    until.astimezone(dtstart.tzinfo).utcoffset()
+                    if until.tzinfo is not None and dtstart.tzinfo is not None
+                    else None
+                )
+                if until_offset is not None:
+                    return until + abs(until_offset)
+
+            offset = dtstart.tzinfo.utcoffset(dtstart) if dtstart.tzinfo else None
+            normalized_until = (
                 until.astimezone(UTC)
                 if type(until) is datetime
                 else datetime(
                     year=until.year, month=until.month, day=until.day, tzinfo=UTC
                 )
-            ) + dtstart.tzinfo.utcoffset(dtstart)
+            )
+            if offset:
+                return normalized_until + offset
+
+            return normalized_until
+
         elif type(dtstart) is date:
             return (
                 until.date() + timedelta(days=1) if type(until) is datetime else until

test/test_data/multi_exdate_same_line_ms.ics

@@ -0,0 +1,47 @@
+BEGIN:VCALENDAR
+METHOD:PUBLISH
+PRODID:Microsoft Exchange Server 2010
+VERSION:2.0
+X-WR-CALNAME:Calendar
+BEGIN:VTIMEZONE
+TZID:Eastern Standard Time
+BEGIN:STANDARD
+DTSTART:16010101T020000
+TZOFFSETFROM:-0400
+TZOFFSETTO:-0500
+RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=1SU;BYMONTH=11
+END:STANDARD
+BEGIN:DAYLIGHT
+DTSTART:16010101T020000
+TZOFFSETFROM:-0500
+TZOFFSETTO:-0400
+RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=2SU;BYMONTH=3
+END:DAYLIGHT
+END:VTIMEZONE
+BEGIN:VEVENT
+DESCRIPTION:Test event that has an RRULE with multiple EXDATE
+RRULE:FREQ=WEEKLY;UNTIL=20220429T150000Z;INTERVAL=1;BYDAY=FR;WKST=MO
+EXDATE;TZID=Eastern Standard Time:20220318T110000,20220401T110000,20220408T
+ 110000
+UID:040000008200R00074P5O7101N82R00800000000R0Q793689428Q801000000000000000
+ 010000000QOPN4SS024R0264S9P0Q7OOQQ16PN399
+SUMMARY:Recurring With Exclusions
+DTSTART;TZID=Eastern Standard Time:20220311T110000
+DTEND;TZID=Eastern Standard Time:20220311T113000
+CLASS:PUBLIC
+PRIORITY:5
+DTSTAMP:20220330T125447Z
+TRANSP:OPAQUE
+STATUS:CONFIRMED
+SEQUENCE:0
+LOCATION:Microsoft Teams Meeting
+X-MICROSOFT-CDO-APPT-SEQUENCE:0
+X-MICROSOFT-CDO-BUSYSTATUS:BUSY
+X-MICROSOFT-CDO-INTENDEDSTATUS:BUSY
+X-MICROSOFT-CDO-ALLDAYEVENT:FALSE
+X-MICROSOFT-CDO-IMPORTANCE:1
+X-MICROSOFT-CDO-INSTTYPE:1
+X-MICROSOFT-DONOTFORWARDMEETING:FALSE
+X-MICROSOFT-DISALLOW-COUNTER:FALSE
+END:VEVENT
+END:VCALENDAR

test/test_icalevents.py

@@ -776,3 +776,22 @@ class ICalEventsTests(unittest.TestCase):
             )
 
         self.assertEqual(len(events), len(times))
+
+    def test_multi_exdate_same_line(self):
+        ical = "test/test_data/multi_exdate_same_line_ms.ics"
+        tz = gettz("America/New_York")
+        start = date(2022, 3, 1)
+        end = date(2022, 5, 1)
+
+        evs = icalevents.events(file=ical, start=start, end=end)
+
+        # parsing starts at 2022-03-01
+        self.assertEqual(evs[0].start, datetime(2022, 3, 11, 11, 0, 0, tzinfo=tz))
+        # 2022-03-18 is excluded by EXDATE rule
+        self.assertEqual(evs[1].start, datetime(2022, 3, 25, 11, 0, 0, tzinfo=tz))
+        # 2022-04-01 is excluded by EXDATE rule
+        # 2022-04-08 is excluded by EXDATE rule
+        self.assertEqual(evs[2].start, datetime(2022, 4, 15, 11, 0, 0, tzinfo=tz))
+        self.assertEqual(evs[3].start, datetime(2022, 4, 22, 11, 0, 0, tzinfo=tz))
+        self.assertEqual(evs[4].start, datetime(2022, 4, 29, 11, 0, 0, tzinfo=tz))
+        # parsing stops at 2022-05-01