diff --git a/searx/search.py b/searx/search.py
index b81112c9d..3619287b9 100644
--- a/searx/search.py
+++ b/searx/search.py
@@ -69,7 +69,7 @@ class SearchQuery:
         self.lang = lang
         self.safesearch = safesearch
         self.pageno = pageno
-        self.time_range = None if time_range in ('', 'None', None) else time_range
+        self.time_range = time_range
         self.timeout_limit = timeout_limit
         self.preferences = preferences
         self.external_bang = external_bang
diff --git a/searx/webadapter.py b/searx/webadapter.py
index 97379b17e..0567c8d34 100644
--- a/searx/webadapter.py
+++ b/searx/webadapter.py
@@ -64,7 +64,8 @@ def get_search_query_from_webapp(preferences, form):
     query_time_range = form.get('time_range')
 
     # check time_range
-    if query_time_range not in ('None', None, '', 'day', 'week', 'month', 'year'):
+    query_time_range = None if query_time_range in ('', 'None') else query_time_range
+    if query_time_range not in (None, 'day', 'week', 'month', 'year'):
         raise SearxParameterException('time_range', query_time_range)
 
     # query_engines