diff --git a/web/run.py b/web/run.py
index 6092549..a26e78b 100755
--- a/web/run.py
+++ b/web/run.py
@@ -1082,26 +1082,32 @@ def get_input_slug_from_query(inp=None):
     return input_slug
 
 
-def get_default_sta_sto(sta=None, sto=None):
+def get_default_sta_sto(sta_str=None, sto_str=None):
 
-    # TODO : maybe get from configuration
     relative_after = config['defaults']['relative_after']
     relative_before = config['defaults']['relative_before']
     before = relativedelta(months=relative_before)
     after = relativedelta(months=relative_after)
 
-    if sta is None and sto is None:
+    if sta_str is None and sto_str is None:
         today = datetime.datetime.now().replace(hour=0, minute=0, second=0)
         sta_date = today - before
         sto_date = today + after
 
-    if sta is None and sto is not None:
-        sto_date = dateparser.isoparse(sto)
+    elif sta_str is not None and sto_str is None:
+        sta_date = dateparser.isoparse(sta_str)
+        sto_date = sta_date + after
+
+    elif sta_str is None and sto_str is not None:
+        sto_date = dateparser.isoparse(sto_str)
         sta_date = sto_date - before
 
-    if sta is not None and sto is None:
-        sta_date = dateparser.isoparse(sta)
-        sto_date = sta_date + after
+    elif sta_str is not None and sto_str is not None:
+        sto_date = dateparser.isoparse(sto_str)
+        sta_date = dateparser.isoparse(sta_str)
+
+    else:
+        raise Exception("IMPOSSIBLE")
 
     return sta_date, sto_date
 
--
libgit2 0.21.2