From 2497dd54254e67e501be5a9ce5e8aaa87c6911c4 Mon Sep 17 00:00:00 2001
From: Oliver <oliver.henry.walters@gmail.com>
Date: Mon, 9 Nov 2026 14:55:48 +1100
Subject: [PATCH] [bug] date import (#13225)

- Handle date values during data import
- reported via sentry.io
---
 src/backend/InvenTree/importer/models.py | 29 ++++++++++++++++++++----
 src/backend/InvenTree/importer/tests.py  | 24 ++++++++++++++++++++
 2 files changed, 49 insertions(+), 4 deletions(-)

diff --git a/src/backend/InvenTree/importer/models.py b/src/backend/InvenTree/importer/models.py
index 796b15ed8c..d8512ac351 100644
--- a/src/backend/InvenTree/importer/models.py
+++ b/src/backend/InvenTree/importer/models.py
@@ -2,7 +2,7 @@
 
 import json
 from collections import OrderedDict
-from datetime import datetime
+from datetime import date, datetime
 from typing import Optional
 
 from django.contrib.auth.models import User
@@ -859,23 +859,44 @@ class DataImportRow(models.Model):
         if commit:
             self.save()
 
-    def convert_date_field(self, value: str) -> Optional[str]:
-        """Convert an incoming date field to the correct format for the database."""
+    def convert_date_field(self, value) -> Optional[str]:
+        """Convert an incoming date field to the correct format for the database.
+
+        The value may be a string (CSV / JSON import), or a native date / datetime
+        object (Excel import via tablib/openpyxl returns date-formatted cells as
+        datetime.datetime objects).
+        """
         if value in [None, '']:
             return None
 
+        # Native date / datetime objects (note: datetime is a subclass of date)
+        if isinstance(value, date):
+            return value.strftime('%Y-%m-%d')
+
+        value = str(value).strip()
+
+        if not value:
+            return None
+
         # Attempt conversion using accepted formats
         date_formats = ['%Y-%m-%d', '%d/%m/%Y', '%m/%d/%Y', '%Y/%m/%d']
 
         for fmt in date_formats:
             try:
-                dt = datetime.strptime(value.strip(), fmt)
+                dt = datetime.strptime(value, fmt)
 
                 # If the date is valid, convert it to the standard format and return
                 return dt.strftime('%Y-%m-%d')
             except ValueError:
                 continue
 
+        # Full ISO-8601 datetime string - e.g. a native datetime which has been
+        # round-tripped through DjangoJSONEncoder when row_data was saved
+        try:
+            return datetime.fromisoformat(value).strftime('%Y-%m-%d')
+        except ValueError:
+            pass
+
         # If none of the formats matched, return the original value
         return value
 
diff --git a/src/backend/InvenTree/importer/tests.py b/src/backend/InvenTree/importer/tests.py
index 13f1e428b3..a36f649ae5 100644
--- a/src/backend/InvenTree/importer/tests.py
+++ b/src/backend/InvenTree/importer/tests.py
@@ -143,6 +143,30 @@ class ImporterTest(ImporterMixin, InvenTreeTestCase):
         row = DataImportRow.objects.get(session=session, row_index=0)
         self.assertEqual(row.row_data['COMMENT'], '2024-05-01T12:30:00')
 
+    def test_convert_date_field(self):
+        """Test conversion of date values for import.
+
+        Regression test for a Sentry crash: "'datetime.datetime' object has no
+        attribute 'strip'". Excel imports provide date cells as native datetime
+        objects, which convert_date_field() previously assumed to be strings.
+        """
+        row = DataImportRow(row_index=0, row_data={})
+
+        for value, expected in [
+            (None, None),
+            ('', None),
+            ('   ', None),
+            (datetime.datetime(2024, 5, 1, 12, 30), '2024-05-01'),
+            (datetime.date(2024, 5, 1), '2024-05-01'),
+            # Native datetime after round-trip through DjangoJSONEncoder
+            ('2024-05-01T12:30:00', '2024-05-01'),
+            (' 2024-05-01 ', '2024-05-01'),
+            ('01/05/2024', '2024-05-01'),
+            ('2024/05/01', '2024-05-01'),
+            ('not a date', 'not a date'),
+        ]:
+            self.assertEqual(row.convert_date_field(value), expected, msg=value)
+
     def test_import_header_whitespace(self):
         """Test that column headers with leading/trailing whitespace are handled correctly.