diff --git a/util.py b/util.py
index dda9f44..5f937e6 100644
--- a/util.py
+++ b/util.py
@@ -1,5 +1,7 @@
 import datetime, time
 
+ONE_DAY = 60*60*24
+
 def getZrange(serv_redis_db, keyCateg, date, topNum, endSubkey=""):
     date_str = getDateStrFormat(date)
     keyname = "{}:{}{}".format(keyCateg, date_str, endSubkey)