fix algorithm for Schedule's dates of month and start working on utilities for scheduling

programs/utils.py

@@ -0,0 +1,43 @@
+from django.utils                   import timezone
+
+from programs.models                import Schedule, Event, Episode,\
+                                           SoundFile, Frequency
+
+
+
+def update_scheduled_events (date):
+    """
+    Update planified events from schedules
+    TODO: notification in case of conflicts?
+    """
+    all_schedules = Schedule.objects().all()
+    schedules = [ schedule
+                    for schedule in models.Schedule.objects().all()
+                    if schedule.match-date(date) ]
+
+    schedules.sort(key = lambda e: e.date)
+
+    for schedule in schedules:
+        if schedule.frequency == Frequency['ponctual']:
+            continue
+
+        ev_date = timezone.datetime(date.year, date.month, date.day,
+                                    schedule.date.hour, schedule.date.minute)
+
+        # if event exists, pass
+        n = Event.objects() \
+                 .filter(date = ev_date, parent__parent = schedule.parent) \
+                 .count()
+        if n:
+            continue
+
+        ep_date = ev_date
+
+        # rerun?
+        if schedule.rerun:
+            schedule = schedule.rerun
+            date_ = schedule.date
+
+        episode = Episode.objects().filter(date = date)
+
+