From 9501e7062c19c6861dedf332930643ffffb2e16c Mon Sep 17 00:00:00 2001
From: chentt <7448203+daydaychen@users.noreply.github.com>
Date: Fri, 19 Jan 2024 14:10:04 +0800
Subject: [PATCH 1/4] fix long period task will never be triggered

---
 django_celery_beat/schedulers.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/django_celery_beat/schedulers.py b/django_celery_beat/schedulers.py
index 846b97a9..810152fc 100644
--- a/django_celery_beat/schedulers.py
+++ b/django_celery_beat/schedulers.py
@@ -84,7 +84,7 @@ def __init__(self, model, app=None):
         self.model = model
 
         if not model.last_run_at:
-            model.last_run_at = self._default_now()
+            model.last_run_at = model.date_changed
             # if last_run_at is not set and
             # model.start_time last_run_at should be in way past.
             # This will trigger the job to run at start_time

From 8a94a48c09afbc1e1769b5d1503d47d44110bf3b Mon Sep 17 00:00:00 2001
From: chentiantian <chentiantian@myhexin.com>
Date: Fri, 14 Jun 2024 10:54:21 +0800
Subject: [PATCH 2/4] fix (schedulers): when model.date_changed is None, use
 _default.now()

---
 django_celery_beat/schedulers.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/django_celery_beat/schedulers.py b/django_celery_beat/schedulers.py
index 810152fc..25f932d6 100644
--- a/django_celery_beat/schedulers.py
+++ b/django_celery_beat/schedulers.py
@@ -84,7 +84,7 @@ def __init__(self, model, app=None):
         self.model = model
 
         if not model.last_run_at:
-            model.last_run_at = model.date_changed
+            model.last_run_at = model.date_changed or self._default_now()
             # if last_run_at is not set and
             # model.start_time last_run_at should be in way past.
             # This will trigger the job to run at start_time

From b3a989fcf4e0e5ad2b3f2f18ee6fa2b6a81f4b00 Mon Sep 17 00:00:00 2001
From: chentiantian <chentiantian@myhexin.com>
Date: Fri, 14 Jun 2024 10:55:11 +0800
Subject: [PATCH 3/4] test (schedulers): add test for when model.last_run_at is
 None

---
 t/unit/test_schedulers.py | 49 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/t/unit/test_schedulers.py b/t/unit/test_schedulers.py
index dbafe666..a6b1d8a0 100644
--- a/t/unit/test_schedulers.py
+++ b/t/unit/test_schedulers.py
@@ -213,6 +213,55 @@ def test_entry_and_model_last_run_at_with_utc_no_use_tz(self, monkeypatch):
         if hasattr(time, "tzset"):
             time.tzset()
 
+    @override_settings(
+        USE_TZ=False,
+        DJANGO_CELERY_BEAT_TZ_AWARE=False
+    )
+    @pytest.mark.usefixtures('depends_on_current_app')
+    @timezone.override('Europe/Berlin')
+    @pytest.mark.celery(timezone='Europe/Berlin')
+    def test_entry_and_model_last_run_at_when_model_changed(self, monkeypatch):
+        old_tz = os.environ.get("TZ")
+        os.environ["TZ"] = "Europe/Berlin"
+        if hasattr(time, "tzset"):
+            time.tzset()
+        assert self.app.timezone.key == 'Europe/Berlin'
+        # simulate last_run_at from DB - not TZ aware but localtime
+        right_now = datetime.utcnow()
+        # make sure to use fixed date time
+        monkeypatch.setattr(self.Entry, '_default_now', lambda o: right_now)
+        m = self.create_model_crontab(
+            crontab(minute='*/10')
+        )
+        m.save()
+        e = self.Entry(m, app=self.app)
+        e.save()
+        m.refresh_from_db()
+
+        # The just created model has no value for last_run_at
+        # so last_run_at should be set to the Entry._default_now()
+        assert m.last_run_at == e.last_run_at
+
+        # If the model has been updated and the entry.last_run_at is None,
+        # entry.last_run_at should be set to the value of model.date_changed.
+        # see #717
+        m2 = self.create_model_crontab(
+            crontab(minute='*/10')
+        )
+        m2.save()
+        m2.refresh_from_db()
+        assert m2.date_changed is not None
+        e2 = self.Entry(m2, app=self.app)
+        e2.save()
+        assert m2.last_run_at == m2.date_changed
+
+        if old_tz is not None:
+            os.environ["TZ"] = old_tz
+        else:
+            del os.environ["TZ"]
+        if hasattr(time, "tzset"):
+            time.tzset()
+
     @override_settings(
         USE_TZ=False,
         DJANGO_CELERY_BEAT_TZ_AWARE=False,

From 96c25ee897dd1d7b4b96595df88fd4aeda74f29c Mon Sep 17 00:00:00 2001
From: chentiantian <chentiantian@myhexin.com>
Date: Sat, 15 Jun 2024 09:30:02 +0800
Subject: [PATCH 4/4] test (scheduler): revise the comment

---
 t/unit/test_schedulers.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/t/unit/test_schedulers.py b/t/unit/test_schedulers.py
index a6b1d8a0..2ff2ea4f 100644
--- a/t/unit/test_schedulers.py
+++ b/t/unit/test_schedulers.py
@@ -238,7 +238,7 @@ def test_entry_and_model_last_run_at_when_model_changed(self, monkeypatch):
         e.save()
         m.refresh_from_db()
 
-        # The just created model has no value for last_run_at
+        # The just created model has no value for date_changed
         # so last_run_at should be set to the Entry._default_now()
         assert m.last_run_at == e.last_run_at