fix: use CalDAV time-range filter for calendar date range queries

get_calendar_events() accepted start/end datetime parameters but called
calendar.events() which fetches all events, silently discarding the
date filters. This caused nc_calendar_list_events and
nc_calendar_get_upcoming_events to return the entire calendar history.

Add _search_events_by_date() helper that builds a CalDAV REPORT query
with a <time-range> filter (RFC 4791 §9.9) for server-side filtering.
Falls back to calendar.events() when no dates are given.

Closes #538

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

nextcloud_mcp_server/client/calendar.py

@@ -255,8 +255,14 @@ class CalendarClient:
         """List events in a calendar within date range."""
         calendar = self._get_calendar(calendar_name)
 
-        # Get all events using caldav library (now with proper filter)
-        events = await calendar.events()
+        if start_datetime or end_datetime:
+            # Build CalDAV REPORT with time-range filter for server-side filtering
+            events = await self._search_events_by_date(
+                calendar, start_datetime, end_datetime
+            )
+        else:
+            # No date filter — fetch all events
+            events = await calendar.events()
 
         result = []
         for event in events:
@@ -274,6 +280,52 @@ class CalendarClient:
         logger.debug(f"Found {len(result)} events")
         return result
 
+    async def _search_events_by_date(
+        self,
+        calendar: AsyncCalendar,
+        start_datetime: Optional[dt.datetime] = None,
+        end_datetime: Optional[dt.datetime] = None,
+    ) -> list:
+        """Execute a CalDAV REPORT with time-range filter."""
+        from caldav.async_collection import AsyncEvent
+        from caldav.elements import cdav, dav
+        from lxml import etree  # type: ignore[import-untyped]
+
+        # Ensure naive datetimes are treated as UTC
+        if start_datetime and start_datetime.tzinfo is None:
+            start_datetime = start_datetime.replace(tzinfo=dt.UTC)
+        if end_datetime and end_datetime.tzinfo is None:
+            end_datetime = end_datetime.replace(tzinfo=dt.UTC)
+
+        # Build comp-filter with time-range (mirrors sync Calendar.build_search_xml_query)
+        inner_comp_filter = cdav.CompFilter(name="VEVENT")
+        inner_comp_filter += cdav.TimeRange(start_datetime, end_datetime)
+        outer_comp_filter = cdav.CompFilter(name="VCALENDAR") + inner_comp_filter
+        filter_element = cdav.Filter() + outer_comp_filter
+
+        query = (
+            cdav.CalendarQuery() + [dav.Prop() + cdav.CalendarData()] + filter_element
+        )
+
+        body = etree.tostring(
+            query.xmlelement(), encoding="utf-8", xml_declaration=True
+        )
+        assert calendar.client is not None
+        response = await calendar.client.report(str(calendar.url), body, depth=1)
+
+        # Parse response (same pattern as AsyncCalendar.search)
+        objects = []
+        response_data = response.expand_simple_props([cdav.CalendarData()])
+        for href, props in response_data.items():
+            if href == str(calendar.url):
+                continue
+            cal_data = props.get(cdav.CalendarData.tag)
+            if cal_data:
+                obj = AsyncEvent(client=calendar.client, data=cal_data, parent=calendar)
+                objects.append(obj)
+
+        return objects
+
     async def create_event(
         self, calendar_name: str, event_data: Dict[str, Any]
     ) -> Dict[str, Any]:

tests/client/calendar/test_calendar_operations.py

@@ -380,6 +380,86 @@ async def test_event_with_url_and_categories(
         raise
 
 
+async def test_list_events_date_range_filtering(
+    nc_client: NextcloudClient, temporary_calendar: str
+):
+    """Test that date range filtering actually excludes events outside the range.
+
+    Reproduces GH-538: get_calendar_events() accepted date range parameters
+    but returned events from the entire calendar history, ignoring date filters.
+    """
+    calendar_name = temporary_calendar
+    past_uid = None
+    future_uid = None
+
+    try:
+        # Create Event A: 30 days in the past
+        past_date = datetime.now() - timedelta(days=30)
+        past_event_data = {
+            "title": f"Past Event {uuid.uuid4().hex[:8]}",
+            "start_datetime": past_date.strftime("%Y-%m-%dT10:00:00"),
+            "end_datetime": past_date.strftime("%Y-%m-%dT11:00:00"),
+            "description": "Event in the past for date range test",
+        }
+        result_past = await nc_client.calendar.create_event(
+            calendar_name, past_event_data
+        )
+        past_uid = result_past["uid"]
+        logger.info(f"Created past event: {past_uid}")
+
+        # Create Event B: 1 day in the future
+        future_date = datetime.now() + timedelta(days=1)
+        future_event_data = {
+            "title": f"Future Event {uuid.uuid4().hex[:8]}",
+            "start_datetime": future_date.strftime("%Y-%m-%dT14:00:00"),
+            "end_datetime": future_date.strftime("%Y-%m-%dT15:00:00"),
+            "description": "Event in the future for date range test",
+        }
+        result_future = await nc_client.calendar.create_event(
+            calendar_name, future_event_data
+        )
+        future_uid = result_future["uid"]
+        logger.info(f"Created future event: {future_uid}")
+
+        # Query with date range: today → 7 days ahead
+        now = datetime.now()
+        week_ahead = now + timedelta(days=7)
+
+        events = await nc_client.calendar.get_calendar_events(
+            calendar_name=calendar_name,
+            start_datetime=now,
+            end_datetime=week_ahead,
+            limit=50,
+        )
+
+        event_uids = [e["uid"] for e in events]
+
+        # Future event (tomorrow) SHOULD be in results
+        assert future_uid in event_uids, (
+            f"Future event {future_uid} should be in date-filtered results"
+        )
+
+        # Past event (30 days ago) should NOT be in results
+        assert past_uid not in event_uids, (
+            f"Past event {past_uid} should be excluded by date range filter "
+            f"(GH-538: date range was being ignored)"
+        )
+
+        logger.info(
+            f"Date range filtering works: {len(events)} events returned, "
+            f"past event correctly excluded"
+        )
+
+    finally:
+        # Cleanup both events
+        for uid in [past_uid, future_uid]:
+            if uid:
+                try:
+                    await nc_client.calendar.delete_event(calendar_name, uid)
+                except Exception as e:
+                    logger.warning(f"Cleanup failed for event {uid}: {e}")
+
+
 async def test_calendar_operations_error_handling(
     nc_client: NextcloudClient,
 ):