diff --git a/matemat/db/facade.py b/matemat/db/facade.py
index b166a32..d3ff681 100644
--- a/matemat/db/facade.py
+++ b/matemat/db/facade.py
@@ -4,7 +4,8 @@ from typing import List, Optional, Any, Type
 
 import crypt
 from hmac import compare_digest
-from datetime import datetime, timedelta
+from datetime import datetime
+import logging
 
 from matemat.db.primitives import User, Product, ReceiptPreference, Receipt,\
     Transaction, Consumption, Deposit, Modification
@@ -577,9 +578,11 @@ class MatematDatabase(object):
         user.balance = old_balance + amount
 
     def check_receipt_due(self, user: User) -> bool:
+        logger = logging.getLogger('matemat.db.facage.check_receipt_due')
         if not isinstance(user.receipt_pref, ReceiptPreference):
             raise TypeError()
         if user.receipt_pref == ReceiptPreference.NONE or user.email is None:
+            logger.debug('Receipt preference None or no e-mail.')
             return False
         with self.db.transaction() as c:
             c.execute('''
@@ -589,8 +592,12 @@ class MatematDatabase(object):
               ON r.user_id = u.user_id
             WHERE u.user_id = :user_id
             ''', [user.id])
+
         last_receipt: datetime = datetime.fromtimestamp(c.fetchone()[0])
         next_receipt_due: datetime = user.receipt_pref.next_receipt_due(last_receipt)
+        logger.debug('Last receipt: %s.', last_receipt)
+        logger.debug('Next receipt: %s.', next_receipt_due)
+        logger.debug('Now: %s.', datetime.utcnow())
 
         return datetime.utcnow() > next_receipt_due