Support inexact conference dates

Closes: #188

tests/test_conference.py

@@ -8,7 +8,7 @@ from typing import Any
 import pytest
 import yaml
 
-from agenda.conference import Conference, get_list
+from agenda.conference import Conference, conference_date_fields, get_list
 from agenda.event import Event
 
 
@@ -298,6 +298,104 @@ class TestGetList:
         assert event.date == datetime(2024, 5, 15, 9, 0)
         assert event.end_date == datetime(2024, 5, 17, 17, 0)
 
+    def test_get_list_nested_exact_dates(self) -> None:
+        """Test reading conference with nested exact dates."""
+        yaml_data = [
+            {
+                "name": "PyCon",
+                "topic": "Python",
+                "location": "Portland",
+                "dates": {
+                    "status": "exact",
+                    "start": date(2024, 5, 15),
+                    "end": date(2024, 5, 17),
+                },
+            }
+        ]
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".yaml", delete=False) as f:
+            yaml.dump(yaml_data, f)
+            f.flush()
+
+            events = get_list(f.name)
+
+        assert len(events) == 1
+        assert events[0].date == date(2024, 5, 15)
+        assert events[0].end_date == date(2024, 5, 17)
+
+    def test_get_list_tentative_dates_do_not_create_conference_event(self) -> None:
+        """Test tentative conference dates are not emitted as calendar events."""
+        yaml_data = [
+            {
+                "name": "FOSDEM",
+                "topic": "FOSDEM",
+                "location": "Brussels",
+                "dates": {
+                    "status": "tentative",
+                    "start": date(2027, 1, 30),
+                    "end": date(2027, 1, 31),
+                    "label": "likely first weekend of February 2027",
+                },
+            }
+        ]
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".yaml", delete=False) as f:
+            yaml.dump(yaml_data, f)
+            f.flush()
+
+            events = get_list(f.name)
+
+        assert events == []
+
+    def test_get_list_approximate_dates_keep_cfp_event(self) -> None:
+        """Test approximate dates do not block CFP reminders."""
+        yaml_data = [
+            {
+                "name": "PyCascades",
+                "topic": "Python",
+                "location": "TBC",
+                "dates": {
+                    "status": "approximate",
+                    "label": "March 2027",
+                    "earliest": date(2027, 3, 1),
+                    "latest": date(2027, 3, 31),
+                },
+                "cfp_end": date(2026, 11, 1),
+            }
+        ]
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".yaml", delete=False) as f:
+            yaml.dump(yaml_data, f)
+            f.flush()
+
+            events = get_list(f.name)
+
+        assert len(events) == 1
+        assert events[0].name == "cfp_end"
+        assert events[0].date == date(2026, 11, 1)
+
+    def test_conference_date_fields_approximate(self) -> None:
+        """Test derived fields for approximate conference dates."""
+        fields = conference_date_fields(
+            {
+                "name": "PyCascades",
+                "topic": "Python",
+                "location": "TBC",
+                "dates": {
+                    "status": "approximate",
+                    "label": "March 2027",
+                    "earliest": date(2027, 3, 1),
+                    "latest": date(2027, 3, 31),
+                },
+            }
+        )
+
+        assert fields["date_status"] == "approximate"
+        assert fields["sort_date"] == date(2027, 3, 1)
+        assert fields["latest_date"] == date(2027, 3, 31)
+        assert fields["display_date"] == "March 2027"
+        assert fields["has_exact_dates"] is False
+
     def test_get_list_invalid_date_order(self) -> None:
         """Test that conferences with end before start raise assertion error."""
         yaml_data = [