fix: preserve time and offset in ISO datetime strings

django_ledger/io/io_core.py

@@ -355,6 +355,7 @@ def validate_io_timestamp(
       are enabled.
     - String inputs are first attempted to be parsed into `date` objects before
       attempting to parse them into `datetime` objects if the initial attempt fails.
+      Parsed datetimes retain their time and UTC offset; date-only strings use midnight.
     - When `no_parse_localdate` is True, the function defaults to returning the
       local time for cases where parsing is not possible.
     """
@@ -374,8 +375,9 @@ def validate_io_timestamp(
             fdt = parse_datetime(dt)
             if not fdt:
                 raise InvalidDateInputError(message=f'Could not parse date from {dt}')
-            elif is_naive(fdt):
+            elif global_settings.USE_TZ and is_naive(fdt):
                 fdt = make_aware(fdt)
+            return fdt
         if global_settings.USE_TZ:
             return make_aware(
                 datetime.combine(

django_ledger/tests/test_io.py

@@ -1,16 +1,73 @@
 from datetime import timedelta, datetime
+from decimal import Decimal
 from random import randint
 from zoneinfo import ZoneInfo
 
 from django.conf import settings
+from django.test import SimpleTestCase, override_settings
 
-from django_ledger.io.io_core import IOValidationError
+from django_ledger.io.io_core import IOValidationError, validate_io_timestamp
 from django_ledger.models import EntityModel
 from django_ledger.tests.base import DjangoLedgerBaseTest
 
 
+@override_settings(TIME_ZONE='America/New_York')
+class IOTimestampTest(SimpleTestCase):
+
+    @override_settings(USE_TZ=True)
+    def test_datetime_strings_preserve_time_and_offset(self):
+        for timestamp in (
+            '2024-07-01T14:35:27.123456Z',
+            '2024-07-01T00:35:27.123456+10:00',
+            '2024-07-01T23:35:27.123456-05:00',
+        ):
+            with self.subTest(timestamp=timestamp):
+                expected = datetime.fromisoformat(timestamp)
+                actual = validate_io_timestamp(timestamp)
+                self.assertEqual(actual, expected)
+                self.assertEqual(actual.utcoffset(), expected.utcoffset())
+
+    def test_naive_datetime_strings_preserve_time(self):
+        timestamp = '2024-07-01T14:35:27.123456'
+        for use_tz in (True, False):
+            with self.subTest(use_tz=use_tz), self.settings(USE_TZ=use_tz):
+                expected = datetime.fromisoformat(timestamp)
+                if use_tz:
+                    expected = expected.replace(tzinfo=ZoneInfo(settings.TIME_ZONE))
+                self.assertEqual(validate_io_timestamp(timestamp), expected)
+
+    def test_date_strings_still_use_local_midnight(self):
+        for use_tz in (True, False):
+            with self.subTest(use_tz=use_tz), self.settings(USE_TZ=use_tz):
+                expected = datetime(2024, 7, 1)
+                if use_tz:
+                    expected = expected.replace(tzinfo=ZoneInfo(settings.TIME_ZONE))
+                self.assertEqual(validate_io_timestamp('2024-07-01'), expected)
+
+
 class IOTest(DjangoLedgerBaseTest):
 
+    def test_commit_txs_preserves_datetime_string(self):
+        entity_model = self.get_random_entity_model()
+        ledger_model = entity_model.create_ledger(name='Timestamp regression')
+        timestamp = '2024-07-01T00:35:27.123456+10:00'
+        transactions = [
+            {
+                'account': self.get_random_account(entity_model, balance_type=tx_type),
+                'amount': Decimal('10.00'),
+                'tx_type': tx_type,
+                'description': 'Timestamp regression',
+            }
+            for tx_type in ('debit', 'credit')
+        ]
+
+        journal_entry, _ = ledger_model.commit_txs(
+            je_timestamp=timestamp,
+            je_txs=transactions,
+        )
+        journal_entry.refresh_from_db()
+        self.assertEqual(journal_entry.timestamp, datetime.fromisoformat(timestamp))
+
     def test_digest_dttm__dttm(self):
         self.assertTrue(settings.USE_TZ, msg='Timezone not enabled.')