From ded6f8543fa7af7eeab4b1941b95e2f3ef99c26c Mon Sep 17 00:00:00 2001
From: Stewart Douglas <sdouglas@quantopian.com>
Date: Tue, 11 Aug 2015 13:32:39 -0400
Subject: [PATCH] BUG: Cast datetime to Timestamp to call value

---
 zipline/assets/assets.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/zipline/assets/assets.py b/zipline/assets/assets.py
index 6fe4122db..0019aaca5 100644
--- a/zipline/assets/assets.py
+++ b/zipline/assets/assets.py
@@ -314,7 +314,7 @@ def lookup_symbol(self, symbol, as_of_date, fuzzy=None):
         so we can find a match by inserting an underscore.
         """
         symbol = symbol.upper()
-        ad_value = normalize_date(as_of_date).value
+        ad_value = pd.Timestamp(normalize_date(as_of_date)).value
 
         if fuzzy is None:
             try: