diff --git a/rowers/templatetags/rowerfilters.py b/rowers/templatetags/rowerfilters.py
index 615dc989..4974bce7 100644
--- a/rowers/templatetags/rowerfilters.py
+++ b/rowers/templatetags/rowerfilters.py
@@ -237,7 +237,10 @@ def durationprint(d,dstring):
     if (d == None):
         return d
     else:
-        return d.strftime(dstring)[:-5]
+        try:
+            return d.strftime(dstring)[:-5]
+        except AttributeError:
+            return None
 
 def getstartenddate(timeperiod):
     s,e = timeperiod.split('/')