diff --git a/gather_new_user.py b/gather_new_user.py
index 60a903c..ed7547f 100644
--- a/gather_new_user.py
+++ b/gather_new_user.py
@@ -54,7 +54,7 @@ def gather_data(last_time, gameid, channelid, ad_channel):
         gameid={gameid}       
         AND channelid={channelid}       
         AND ad_channel={ad_channel}       
-        AND register_time <{last_time}"""
+        AND register_time <'{last_time}'"""
 
     try:
         data = mydb.query(total_user_sql)
@@ -71,7 +71,7 @@ def gather_data(last_time, gameid, channelid, ad_channel):
             gameid={gameid}       
             AND channelid={channelid}       
             AND ad_channel={ad_channel}       
-            AND register_time BETWEEN {begin} AND {last_time}"""
+            AND register_time BETWEEN '{begin}' AND '{last_time}'"""
     try:
         data = mydb.query(new_user_sql)
         new_user = data[0][0]