diff --git a/smash/web/importer/csv_subject_import_reader.py b/smash/web/importer/csv_subject_import_reader.py
index 44a30f6f50d9609d69a9e09e9af1ca6ba58c782f..7acb8d5cfd787158ed7540c8a231cf3b68e375c7 100644
--- a/smash/web/importer/csv_subject_import_reader.py
+++ b/smash/web/importer/csv_subject_import_reader.py
@@ -1,15 +1,13 @@
 import csv
-import datetime
 import logging
 from typing import List, Type, Tuple
 
-import pytz
 from django.db import models
 from django.db.models import Field
 
 from web.models import StudySubject, Subject, SubjectImportData
-from .subject_import_reader import SubjectImportReader
 from .etl_common import EtlCommon
+from .subject_import_reader import SubjectImportReader
 
 logger = logging.getLogger(__name__)
 
@@ -53,11 +51,11 @@ class CsvSubjectImportReader(SubjectImportReader):
 
         if table == Subject:
             old_val = getattr(study_subject.subject, field.name)
-            setattr(study_subject.subject, field.name, self.get_new_value(old_val, field.name, value))
+            setattr(study_subject.subject, field.name, self.get_new_value(old_val, value))
         elif table == StudySubject:
             old_val = getattr(study_subject, field.name)
             print(field.name + ": " + str(old_val) + " - " + str(value))
-            setattr(study_subject, field.name, self.get_new_value(old_val, field.name, value))
+            setattr(study_subject, field.name, self.get_new_value(old_val, value))
         else:
             logger.warning("Don't know how to handle column " + column_name + " with data " + value)
 
@@ -76,12 +74,3 @@ class CsvSubjectImportReader(SubjectImportReader):
                         found = True
                 if not found:
                     self.mappings[field.name] = object_type, field
-
-    def get_date(self, value):
-        try:
-            result = datetime.datetime.strptime(value, self.etl_data.date_format)
-            result.replace(tzinfo=pytz.UTC)
-            return result
-        except ValueError:
-            logger.warning("Invalid date: " + value)
-            return None
diff --git a/smash/web/importer/etl_common.py b/smash/web/importer/etl_common.py
index b18f78aed1cecfc000eedfc0c12dfa88fcba8e84..7538e8c37f176817c938f866246282c708fe5b3d 100644
--- a/smash/web/importer/etl_common.py
+++ b/smash/web/importer/etl_common.py
@@ -3,6 +3,7 @@ import datetime
 import logging
 from typing import Type, Optional
 
+import pytz
 from django.db import models
 
 from web.models import Provenance
@@ -15,23 +16,17 @@ class EtlCommon:
     def __init__(self, import_data: EtlData):
         self.etl_data = import_data
 
-    def get_new_date_value(self, old_value: datetime, column_name: str, new_value: str) -> datetime:
-        if old_value is None or old_value == "":
-            try:
-                result = datetime.datetime.strptime(new_value, self.etl_data.date_format)
-            except ValueError:
-                logger.warning("Invalid date: " + new_value)
-                result = old_value
+    def get_date(self, value):
+        try:
+            result = datetime.datetime.strptime(value, self.etl_data.date_format)
+            result.replace(tzinfo=pytz.UTC)
             return result
-        if new_value is None or new_value == "":
-            return old_value
-        logger.warning(
-            "Contradicting entries in csv file for column: " + column_name + "(" + new_value + "," + old_value +
-            "). Latest value will be used")
-        return datetime.datetime.strptime(new_value, self.etl_data.date_format)
+        except ValueError:
+            logger.warning("Invalid date: " + value)
+            return None
 
     @staticmethod
-    def get_new_value(old_value: object, column_name: str, new_value: object) -> object:
+    def get_new_value(old_value: object, new_value: object) -> object:
         if old_value is None or old_value == "":
             return new_value
         if new_value is None or new_value == "":
@@ -43,9 +38,6 @@ class EtlCommon:
                 return old_value
             if old_value in new_value:
                 return new_value
-        logger.warning(
-            "Contradicting entries in csv file for column: " + column_name + "(" + str(new_value) + "," + str(
-                old_value) + "). Latest value will be used")
         return new_value
 
     def create_provenance_and_change_data(self, object_to_change: models.Model, field_name: str, new_value: object,
diff --git a/smash/web/importer/importer.py b/smash/web/importer/importer.py
index 28b33242fc94d6e35f76968705dc0d997b0acf19..84f68094ad43291e67a2d1db4165b0a2eff480d5 100644
--- a/smash/web/importer/importer.py
+++ b/smash/web/importer/importer.py
@@ -57,7 +57,7 @@ class Importer(EtlCommon):
                         field.get_internal_type() == "DateField" or \
                         field.get_internal_type() is "BooleanField":
                     old_value = getattr(db_study_subject.subject, field.name)
-                    new_value = self.get_new_value(old_value, field.name, getattr(study_subject.subject, field.name))
+                    new_value = self.get_new_value(old_value, getattr(study_subject.subject, field.name))
                     self.create_provenance_and_change_data(db_study_subject.subject, field.name, new_value, Subject)
             db_study_subject.subject.save()
 
@@ -66,7 +66,7 @@ class Importer(EtlCommon):
                         field.get_internal_type() == "DateField" or \
                         field.get_internal_type() is "BooleanField":
                     old_value = getattr(db_study_subject, field.name)
-                    new_value = self.get_new_value(old_value, field.name, getattr(study_subject, field.name))
+                    new_value = self.get_new_value(old_value, getattr(study_subject, field.name))
                     self.create_provenance_and_change_data(db_study_subject, field.name, new_value, StudySubject)
             db_study_subject.save()