diff --git a/accountant/models/accounts.py b/accountant/models/accounts.py
index be6bba8..566bfbf 100644
--- a/accountant/models/accounts.py
+++ b/accountant/models/accounts.py
@@ -69,15 +69,13 @@ class Account(db.Model):
         query = db.session.query(
             db.func.sum(
                 db.case(
-                    [(db.func.sign(Operation.value) == -1,
-                        Operation.value)],
+                    [(db.func.sign(Operation.value) == -1, Operation.value)],
                     else_=0
                 )
             ).label("expenses"),
             db.func.sum(
                 db.case(
-                    [(db.func.sign(Operation.value) == 1,
-                        Operation.value)],
+                    [(db.func.sign(Operation.value) == 1, Operation.value)],
                     else_=0
                 )
             ).label("revenues"),
diff --git a/accountant/models/scheduled_operations.py b/accountant/models/scheduled_operations.py
index 9535802..d8de21e 100644
--- a/accountant/models/scheduled_operations.py
+++ b/accountant/models/scheduled_operations.py
@@ -99,29 +99,27 @@ class ScheduledOperation(db.Model):
         stop_date = arrow.get(self.stop_date)
 
         # Iterate over the range.
-        for c_date in arrow.Arrow.range(
-            "month", start_date, stop_date
-        )[::self.frequency]:
+        date_range = arrow.Arrow.range("month", start_date, stop_date)
+        dates = date_range[::self.frequency]
+        for date in dates:
             # If a date day is below the first date day, next dates will not
             # have the right day.
             day = min(self.day, monthrange(
-                c_date.year, c_date.month)[1])
+                date.year, date.month)[1])
 
-            c_date = c_date.replace(day=day)
+            date = date.replace(day=day)
 
             # Search if a close operation exists.
 
-            if not db.session.query(
-                Operation
-            ).filter(
-                Operation.account_id == self.account_id,
-                Operation.scheduled_operation_id == self.id,
-                Operation.operation_date >= c_date.replace(weeks=-2).date(),
-                Operation.operation_date <= c_date.replace(weeks=+2).date()
+            if not db.session.query(Operation).filter(
+                    Operation.account_id == self.account_id,
+                    Operation.scheduled_operation_id == self.id,
+                    Operation.operation_date >= date.replace(weeks=-2).date(),
+                    Operation.operation_date <= date.replace(weeks=+2).date()
             ).count():
                 # Create not confirmed operation if not found.
                 operation = Operation(
-                    operation_date=c_date.date(),
+                    operation_date=date.date(),
                     label=self.label,
                     value=self.value,
                     category=self.category,