diff --git a/homeassistant/components/local_calendar/diagnostics.py b/homeassistant/components/local_calendar/diagnostics.py
new file mode 100644
index 0000000000..51b53ff007
--- /dev/null
+++ b/homeassistant/components/local_calendar/diagnostics.py
@@ -0,0 +1,27 @@
+"""Provides diagnostics for local calendar."""
+
+import datetime
+from typing import Any
+
+from ical.diagnostics import redact_ics
+
+from homeassistant.config_entries import ConfigEntry
+from homeassistant.core import HomeAssistant
+from homeassistant.util import dt as dt_util
+
+from .const import DOMAIN
+
+
+async def async_get_config_entry_diagnostics(
+    hass: HomeAssistant, config_entry: ConfigEntry
+) -> dict[str, Any]:
+    """Return diagnostics for a config entry."""
+    payload: dict[str, Any] = {
+        "now": dt_util.now().isoformat(),
+        "timezone": str(dt_util.DEFAULT_TIME_ZONE),
+        "system_timezone": str(datetime.datetime.utcnow().astimezone().tzinfo),
+    }
+    store = hass.data[DOMAIN][config_entry.entry_id]
+    ics = await store.async_load()
+    payload["ics"] = "\n".join(redact_ics(ics))
+    return payload
diff --git a/tests/components/local_calendar/snapshots/test_diagnostics.ambr b/tests/components/local_calendar/snapshots/test_diagnostics.ambr
new file mode 100644
index 0000000000..e61b9da7a9
--- /dev/null
+++ b/tests/components/local_calendar/snapshots/test_diagnostics.ambr
@@ -0,0 +1,32 @@
+# serializer version: 1
+# name: test_api_date_time_event
+  dict({
+    'ics': '''
+      BEGIN:VCALENDAR
+      PRODID:-//github.com/allenporter/ical//4.5.0//EN
+      VERSION:***
+      BEGIN:VEVENT
+      DTSTAMP:20230313T190500
+      UID:***
+      DTSTART:19970714T110000
+      DTEND:19970714T220000
+      SUMMARY:***
+      CREATED:20230313T190500
+      RRULE:FREQ=DAILY
+      SEQUENCE:***
+      END:VEVENT
+      END:VCALENDAR
+    ''',
+    'now': '2023-03-13T13:05:00-06:00',
+    'system_timezone': 'tzlocal()',
+    'timezone': 'America/Regina',
+  })
+# ---
+# name: test_empty_calendar
+  dict({
+    'ics': '',
+    'now': '2023-03-13T13:05:00-06:00',
+    'system_timezone': 'tzlocal()',
+    'timezone': 'America/Regina',
+  })
+# ---
diff --git a/tests/components/local_calendar/test_diagnostics.py b/tests/components/local_calendar/test_diagnostics.py
new file mode 100644
index 0000000000..8b033cf4fd
--- /dev/null
+++ b/tests/components/local_calendar/test_diagnostics.py
@@ -0,0 +1,62 @@
+"""Tests for diagnostics platform of local calendar."""
+
+from freezegun import freeze_time
+import pytest
+from syrupy.assertion import SnapshotAssertion
+
+from homeassistant.core import HomeAssistant
+from homeassistant.setup import async_setup_component
+
+from .conftest import TEST_ENTITY, ClientFixture
+
+from tests.common import MockConfigEntry
+from tests.components.diagnostics import get_diagnostics_for_config_entry
+from tests.typing import ClientSessionGenerator
+
+
+@pytest.fixture(autouse=True)
+async def setup_diag(hass):
+    """Set up diagnostics platform."""
+    assert await async_setup_component(hass, "diagnostics", {})
+
+
+@freeze_time("2023-03-13 12:05:00-07:00")
+async def test_empty_calendar(
+    hass: HomeAssistant,
+    setup_integration: None,
+    hass_client: ClientSessionGenerator,
+    config_entry: MockConfigEntry,
+    snapshot: SnapshotAssertion,
+) -> None:
+    """Test diagnostics against an empty calendar."""
+    data = await get_diagnostics_for_config_entry(hass, hass_client, config_entry)
+    assert data == snapshot
+
+
+@freeze_time("2023-03-13 12:05:00-07:00")
+async def test_api_date_time_event(
+    hass: HomeAssistant,
+    setup_integration: None,
+    config_entry: MockConfigEntry,
+    hass_client: ClientSessionGenerator,
+    ws_client: ClientFixture,
+    snapshot: SnapshotAssertion,
+) -> None:
+    """Test an event with a start/end date time."""
+
+    client = await ws_client()
+    await client.cmd_result(
+        "create",
+        {
+            "entity_id": TEST_ENTITY,
+            "event": {
+                "summary": "Bastille Day Party",
+                "dtstart": "1997-07-14T17:00:00+00:00",
+                "dtend": "1997-07-15T04:00:00+00:00",
+                "rrule": "FREQ=DAILY",
+            },
+        },
+    )
+
+    data = await get_diagnostics_for_config_entry(hass, hass_client, config_entry)
+    assert data == snapshot