Remove option to use run_after with timedelta

Managing when it applies and which timezone can be quite complex.

django/tasks/task.py

@@ -1,12 +1,11 @@
 from dataclasses import dataclass, field, replace
-from datetime import datetime, timedelta
+from datetime import datetime
 from inspect import iscoroutinefunction
 from typing import Any, Callable, Dict, Optional, Type
 
 from asgiref.sync import async_to_sync, sync_to_async
 
 from django.db.models.enums import TextChoices
-from django.utils import timezone
 from django.utils.translation import gettext_lazy as _
 
 from .exceptions import ResultDoesNotExist
@@ -88,10 +87,7 @@ class Task:
         if queue_name is not None:
             changes["queue_name"] = queue_name
         if run_after is not None:
-            if isinstance(run_after, timedelta):
-                changes["run_after"] = timezone.now() + run_after
-            else:
-                changes["run_after"] = run_after
+            changes["run_after"] = run_after
         if backend is not None:
             changes["backend"] = backend
 

docs/ref/tasks.txt

@@ -85,10 +85,6 @@ Attributes of ``Task`` cannot be modified.
     * :attr:`queue_name <Task.queue_name>`
     * :attr:`run_after <Task.run_after>`
 
-    ``run_after`` may also be provided as a :class:`timedelta <datetime.timedelta>`,
-    which is used relative to the current time (when ``using`` is called), or a
-    timezone-aware :class:`datetime <datetime.datetime>`.
-
 .. method:: Task.enqueue(*args, **kwargs)
 
     Enqueue the task for later execution.

tests/tasks/test_tasks.py

@@ -1,5 +1,5 @@
 import dataclasses
-from datetime import datetime, timedelta
+from datetime import datetime
 
 from django.tasks import (
     DEFAULT_QUEUE_NAME,
@@ -97,10 +97,6 @@ class TaskTestCase(SimpleTestCase):
 
         self.assertIsNone(test_tasks.noop_task.run_after)
         self.assertEqual(test_tasks.noop_task.using(run_after=now).run_after, now)
-        self.assertIsInstance(
-            test_tasks.noop_task.using(run_after=timedelta(hours=1)).run_after,
-            datetime,
-        )
         self.assertIsNone(test_tasks.noop_task.run_after)
 
     def test_using_unknown_backend(self):