From 952210e1d1c3a6f17dac1c29c3be24bf3be9bc3f Mon Sep 17 00:00:00 2001
From: Peter Bieringer <pb@bieringer.de>
Date: Sun, 21 Jun 2026 16:39:08 +0200
Subject: [PATCH 1/3] add PERIOD handling

---
 vobject/icalendar.py | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/vobject/icalendar.py b/vobject/icalendar.py
index 52ff94b..ae30411 100644
--- a/vobject/icalendar.py
+++ b/vobject/icalendar.py
@@ -876,14 +876,20 @@ def transformFromNative(obj):
             obj.value_param = 'DATE'
             obj.value = ','.join([dateToString(val) for val in obj.value])
             return obj
-        # Fixme: handle PERIOD case
         else:
             if obj.isNative:
                 obj.isNative = False
                 transformed = []
                 tzid = None
                 for val in obj.value:
-                    if tzid is None and type(val) == datetime.datetime:
+                    if obj.value_param == "PERIOD":
+                        if type(val[0]) is datetime.datetime and type(val[1]) is datetime.timedelta:
+                            transformed.append(periodToString(val))
+                            continue
+                        elif type(val[0]) is datetime.datetime and type(val[1]) is datetime.datetime:
+                            transformed.append(dateTimeToString(val[0]) + '/' + dateTimeToString(val[1]))
+                            continue
+                    if tzid is None and type(val) is datetime.datetime:
                         tzid = TimezoneComponent.registerTzinfo(val.tzinfo)
                         if tzid is not None:
                             obj.tzid_param = tzid

From 84b8e616c7ef067f4eafeaf3c15a057d10ccda7d Mon Sep 17 00:00:00 2001
From: Peter Bieringer <pb@bieringer.de>
Date: Sun, 21 Jun 2026 16:43:52 +0200
Subject: [PATCH 2/3] make lint happy

---
 vobject/icalendar.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/vobject/icalendar.py b/vobject/icalendar.py
index ae30411..ef9b430 100644
--- a/vobject/icalendar.py
+++ b/vobject/icalendar.py
@@ -886,7 +886,7 @@ def transformFromNative(obj):
                         if type(val[0]) is datetime.datetime and type(val[1]) is datetime.timedelta:
                             transformed.append(periodToString(val))
                             continue
-                        elif type(val[0]) is datetime.datetime and type(val[1]) is datetime.datetime:
+                        if type(val[0]) is datetime.datetime and type(val[1]) is datetime.datetime:
                             transformed.append(dateTimeToString(val[0]) + '/' + dateTimeToString(val[1]))
                             continue
                     if tzid is None and type(val) is datetime.datetime:

From 03cf614b487d51f305d1e342532e7592a5038aa0 Mon Sep 17 00:00:00 2001
From: David Arnold <d@0x1.org>
Date: Wed, 5 Aug 2026 11:41:54 +1000
Subject: [PATCH 3/3] Add test for RRULE using RDATE with PERIOD.

See issue py-vobject/vobject#129 and Kozea/Radicale#2165.
---
 tests.py | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/tests.py b/tests.py
index 0c1a6e6..81d2678 100644
--- a/tests.py
+++ b/tests.py
@@ -284,6 +284,28 @@ def test_periodBehavior(self):
             'TEST:20060216T100000/PT2H,20060516T100000/PT2H'
         )
 
+    def test_rrdate_with_period(self):
+        """
+        Test round-trip parsing and serialization of an RRULE with
+        an RDATE using a PERIOD.
+        """
+
+        raw = "BEGIN:VCALENDAR\r\n" \
+            + "VERSION:2.0\r\n" \
+            + "PRODID:test\r\n" \
+            + "BEGIN:VEVENT\r\n" \
+            + "UID:test\r\n" \
+            + "DTSTART:20000101T000000Z\r\n" \
+            + "DURATION:PT1H\r\n" \
+            + "DTSTAMP:20000101T000000Z\r\n" \
+            + "RDATE;VALUE=PERIOD:20000102T000000Z/PT2H\r\n" \
+            + "RRULE:FREQ=WEEKLY\r\n" \
+            + "END:VEVENT\r\n" \
+            + "END:VCALENDAR\r\n"
+        obj = base.readOne(raw)
+        serialized = obj.serialize()
+        self.assertEqual(raw, serialized)
+
 
 class TestVTodo(unittest.TestCase):
     """