diff --git a/ExtensionCrawler/archive.py b/ExtensionCrawler/archive.py
index 1ff2bd0..b2aff87 100644
--- a/ExtensionCrawler/archive.py
+++ b/ExtensionCrawler/archive.py
@@ -36,7 +36,7 @@ import shutil
 import tarfile
 import tempfile
 import time
-
+import dateutil.parser
 
 class Error(Exception):
     pass
@@ -177,13 +177,15 @@ def last_modified_http_date(path):
     return httpdate(dateutil.parser.parse(last_modified_utc_date(path)))
 
 
-def last_crx(archivedir, extid):
+def last_crx(archivedir, extid,date=None):
     last_crx = ""
     tar = os.path.join(archivedir, get_local_archive_dir(extid),
                        extid + ".tar")
     if os.path.exists(tar):
         t = tarfile.open(tar, 'r')
-        old_crxs = sorted([x.name for x in t.getmembers() if x.name.endswith(".crx") and x.size > 0])
+        old_crxs = sorted([x.name for x in t.getmembers() if x.name.endswith(".crx")
+                           and x.size > 0
+                           and (date is None or (dateutil.parser.parse(os.path.split(os.path.split(x.name)[0])[1]) <= date))])
         t.close()
         if old_crxs != []:
             last_crx = old_crxs[-1]