Update "add day" ammount calc

apps/payment/models.py

@@ -167,8 +167,19 @@ class SchoolPayment(Payment):
             models.Sum('month_price'),
         )
         if self.add_days:
+            _school_payment = SchoolPayment.objects.filter(
+                add_days=False,
+                date_start__lte=self.date_start,
+                date_end__gte=self.date_end,
+                status__in=[
+                    Pingback.PINGBACK_TYPE_REGULAR,
+                    Pingback.PINGBACK_TYPE_GOODWILL,
+                    Pingback.PINGBACK_TYPE_RISK_REVIEWED_ACCEPTED,
+                ],
+            ).last()
             weekday_count = weekday_in_date_range(self.date_start, self.date_end, self.weekdays[0])
-            month_price_sum = aggregate.get('month_price__sum', 0) * weekday_count / 30
+            all_weekday_count = weekday_in_date_range(_school_payment.date_start, _school_payment.date_end, self.weekdays[0])
+            month_price_sum = aggregate.get('month_price__sum', 0) * weekday_count // all_weekday_count
         else:
             month_price_sum = aggregate.get('month_price__sum', 0)
         if month_price_sum > config.SERVICE_DISCOUNT_MIN_AMOUNT:

apps/payment/views.py

@@ -107,7 +107,7 @@ class SchoolBuyView(TemplateView):
                 user=request.user,
                 weekdays=weekdays,
                 date_start=now().date(),
-                date_end=now().date(),
+                date_end=_school_payment.date_end,
                 add_days=True,
             )
             if school_payment.amount <= 0: