Set modified time on case zip entries (#24803)

* set modified time on case download zip entries

Case download zip entries were written with the zip format's 1980 placeholder date, so extracted files showed a blank or 1980 modified date. Each entry now uses the export's recording start time, converted with the UI timezone since zip times have no zone and extractors read them as local time.

* clamp case zip entry dates to 1980

frigate/api/export.py

@@ -12,6 +12,7 @@ from collections import deque
 from collections.abc import Iterator
 from pathlib import Path
 from urllib.parse import quote
+from zoneinfo import ZoneInfo, ZoneInfoNotFoundError
 
 import psutil
 from fastapi import APIRouter, Depends, Query, Request
@@ -81,7 +82,7 @@ from frigate.record.export import (
 )
 from frigate.util.path import sanitize_contained_path
 from frigate.util.recording_coverage import recording_overlap
-from frigate.util.time import is_current_hour
+from frigate.util.time import get_normalized_tz_name, is_current_hour
 
 logger = logging.getLogger(__name__)
 
@@ -442,7 +443,29 @@ def _unique_archive_name(export: Export, used: set[str]) -> str:
     return candidate
 
 
-def _stream_case_archive(exports: list[Export]) -> Iterator[bytes]:
+def _archive_entry(
+    export: Export, arcname: str, tz_name: str | None
+) -> zipfile.ZipInfo:
+    """Zip entry stamped with the export's recording start time.
+
+    Zip times carry no zone and extractors read them as local time, so the
+    timestamp is converted with the UI timezone rather than the container's.
+    """
+    tz = None
+    if tz_name:
+        try:
+            tz = ZoneInfo(get_normalized_tz_name(tz_name))
+        except (ValueError, ZoneInfoNotFoundError):
+            pass
+
+    start = datetime.datetime.fromtimestamp(float(export.date), tz=tz)
+
+    # zip can't represent dates before 1980
+    date_time = max(start.timetuple()[:6], (1980, 1, 1, 0, 0, 0))
+    return zipfile.ZipInfo(arcname, date_time=date_time)
+
+
+def _stream_case_archive(exports: list[Export], tz_name: str | None) -> Iterator[bytes]:
     """Yield bytes of a zip archive built from the given exports' mp4 files."""
     buffer = _StreamingZipBuffer()
     used_names: set[str] = set()
@@ -460,9 +483,10 @@ def _stream_case_archive(exports: list[Export]) -> Iterator[bytes]:
                 continue
 
             arcname = _unique_archive_name(export, used_names)
+            zinfo = _archive_entry(export, arcname, tz_name)
 
             with (
-                archive.open(arcname, mode="w", force_zip64=True) as entry,
+                archive.open(zinfo, mode="w", force_zip64=True) as entry,
                 source.open("rb") as src,
             ):
                 while True:
@@ -501,6 +525,7 @@ def _content_disposition(filename: str, ascii_fallback: str) -> str:
     description="Streams a zip archive containing every completed export's mp4 for the given case.",
 )
 def download_export_case(
+    request: Request,
     case_id: str,
     allowed_cameras: list[str] = Depends(get_allowed_cameras_for_filter),
 ):
@@ -533,7 +558,7 @@ def download_export_case(
         archive_base = case_id
 
     return StreamingResponse(
-        _stream_case_archive(exports),
+        _stream_case_archive(exports, request.app.frigate_config.ui.timezone),
         media_type="application/zip",
         headers={
             "Content-Disposition": _content_disposition(

frigate/test/test_export.py

@@ -4,7 +4,7 @@ import unittest
 from pathlib import Path
 from unittest.mock import MagicMock, patch
 
-from frigate.api.export import _unique_archive_name
+from frigate.api.export import _archive_entry, _unique_archive_name
 from frigate.const import MAX_PLAYLIST_SECONDS
 from frigate.models import Export
 from frigate.record.export import (
@@ -220,6 +220,38 @@ class TestUniqueArchiveName(unittest.TestCase):
         )
 
 
+class TestArchiveEntry(unittest.TestCase):
+    """Tests for the modified time stamped on case download zip entries."""
+
+    def build_export(self) -> Export:
+        return Export(
+            id="front_door_abc123",
+            camera="front_door",
+            name="front door",
+            date=1756000000.0,
+            video_path="/media/frigate/exports/front_door_abc123.mp4",
+            thumb_path="/media/frigate/exports/front_door_abc123.webp",
+            in_progress=False,
+        )
+
+    def test_uses_start_time_in_ui_timezone(self):
+        zinfo = _archive_entry(self.build_export(), "a.mp4", "America/New_York")
+        self.assertEqual(zinfo.date_time, (2025, 8, 23, 21, 46, 40))
+
+    def test_clamps_dates_before_1980(self):
+        export = self.build_export()
+        export.date = 100
+        zinfo = _archive_entry(export, "a.mp4", "UTC")
+        self.assertEqual(zinfo.date_time, (1980, 1, 1, 0, 0, 0))
+
+    def test_invalid_timezone_falls_back_to_local_time(self):
+        zinfo = _archive_entry(self.build_export(), "a.mp4", "Not/A_Real_Zone")
+        self.assertEqual(
+            zinfo.date_time,
+            _archive_entry(self.build_export(), "a.mp4", None).date_time,
+        )
+
+
 if __name__ == "__main__":
     unittest.main()