Make weekdays selectable in backend

aleksis/apps/chronos/preferences.py

@@ -122,3 +122,25 @@ class SupervisionEventFeedColor(StringPreference):
     verbose_name = _("Supervision calendar feed color")
     widget = ColorWidget
     required = True
+
+@site_preferences_registry.register
+class DaysInCalendar(MultipleChoicePreference):
+    section = chronos
+    name = "days_in_calendar"
+    default = ["1", "2", "3", "4", "5"]
+    verbose_name = _("Days of the week that appear in the timetable")
+    choices = [
+        ("1", _("Monday")),
+        ("2", _("Tuesday")),
+        ("3", _("Wednesday")),
+        ("4", _("Thursday")),
+        ("5", _("Friday")),
+        ("6", _("Saturday")),
+        ("0", _("Sunday")),
+    ]
+    required = True
+
+    def validate(self, value):
+        for v in value:
+            if int(v) not in self.get_choice_values():
+                raise ValidationError(f"{v} is not a valid choice")