Fix crontab that use month of year and day of month

This patch fix the use of periodic tasks with
both month_of_year and day_of_month.

Before this patch, in July for a tasks that should
run in February, the periodic task run again and
again. Celery believes it is 5 months late when
it is 7 month in advance.

celery/schedules.py

@@ -391,7 +391,11 @@ class crontab(schedule):
                 flag = (datedata.dom == len(days_of_month) or
                         day_out_of_range(datedata.year,
                                          months_of_year[datedata.moy],
-                                         days_of_month[datedata.dom]))
+                                         days_of_month[datedata.dom]) or
+                        (self.maybe_make_aware(datetime(datedata.year,
+                         months_of_year[datedata.moy],
+                         days_of_month[datedata.dom])) < last_run_at))
+
                 if flag:
                     datedata.dom = 0
                     datedata.moy += 1
@@ -457,6 +461,7 @@ class crontab(schedule):
 
     def remaining_delta(self, last_run_at, ffwd=ffwd):
         last_run_at = self.maybe_make_aware(last_run_at)
+        now = self.maybe_make_aware(self.now())
         dow_num = last_run_at.isoweekday() % 7  # Sunday is day 0, not day 7
 
         execute_this_date = (last_run_at.month in self.month_of_year and
@@ -464,6 +469,9 @@ class crontab(schedule):
                              dow_num in self.day_of_week)
 
         execute_this_hour = (execute_this_date and
+                             last_run_at.day == now.day and
+                             last_run_at.month == now.month and
+                             last_run_at.year == now.year and
                              last_run_at.hour in self.hour and
                              last_run_at.minute < max(self.minute))
 
@@ -500,7 +508,6 @@ class crontab(schedule):
                     delta = self._delta_to_next(last_run_at,
                                                 next_hour, next_minute)
 
-        now = self.maybe_make_aware(self.now())
         return self.to_local(last_run_at), delta, self.to_local(now)
 
     def remaining_estimate(self, last_run_at, ffwd=ffwd):

celery/tests/tasks/test_tasks.py

@@ -1,5 +1,5 @@
 from __future__ import absolute_import
-
+import time
 from collections import Callable
 from datetime import datetime, timedelta
 from functools import wraps
@@ -635,6 +635,14 @@ def monthly():
     pass
 
 
+@periodic_task(run_every=crontab(hour=22,
+                                 day_of_week='*',
+                                 month_of_year='2',
+                                 day_of_month='26,27,28'))
+def monthly_moy():
+    pass
+
+
 @periodic_task(run_every=crontab(hour=7, minute=30,
                                  day_of_week='thursday',
                                  day_of_month='8-14',
@@ -1256,6 +1264,43 @@ class test_crontab_is_due(AppCase):
         self.assertFalse(due)
         self.assertEqual(remaining, 4 * 24 * 60 * 60 - 3 * 60 * 60)
 
+
+    @patch_crontab_nowfun(monthly_moy, datetime(2014, 2, 26, 22, 0))
+    def test_monthly_moy_execution_is_due(self):
+        due, remaining = monthly_moy.run_every.is_due(
+            datetime(2013, 7, 4, 10, 0))
+        self.assertTrue(due)
+        self.assertEqual(remaining, 60.)
+
+    @patch_crontab_nowfun(monthly_moy, datetime(2013, 6, 28, 14, 30))
+    def test_monthly_moy_execution_is_not_due(self):
+        
+        due, remaining = monthly_moy.run_every.is_due(
+            datetime(2013, 6, 28, 22, 14))
+        self.assertFalse(due)
+        attempt = (time.mktime(datetime(2014, 2, 26, 22, 0).timetuple())
+                   - time.mktime(datetime(2013, 6, 28, 14, 30).timetuple())
+                   - 60 * 60
+                   ) 
+        self.assertEqual(remaining, attempt)
+
+    @patch_crontab_nowfun(monthly_moy, datetime(2014, 2, 26, 22, 0))
+    def test_monthly_moy_execution_is_due2(self):
+        due, remaining = monthly_moy.run_every.is_due(
+            datetime(2013, 2, 28, 10, 0))
+        self.assertTrue(due)
+        self.assertEqual(remaining, 60.)
+
+    @patch_crontab_nowfun(monthly_moy, datetime(2014, 2, 26, 21, 0))
+    def test_monthly_moy_execution_is_not_due2(self):
+        
+        due, remaining = monthly_moy.run_every.is_due(
+            datetime(2013, 6, 28, 22, 14))
+        self.assertFalse(due)
+        attempt = 60 * 60
+        self.assertEqual(remaining, attempt)
+
+
     @patch_crontab_nowfun(yearly, datetime(2010, 3, 11, 7, 30))
     def test_yearly_execution_is_due(self):
         due, remaining = yearly.run_every.is_due(