diff --git a/composer/schema/field.py b/composer/schema/field.py
index 4619f95..16e5427 100644
--- a/composer/schema/field.py
+++ b/composer/schema/field.py
@@ -304,7 +304,10 @@ class DateFieldInstance(NumberFieldInstance):
             return ''
         if isinstance(value, basestring):
             return value
-        return strftime('%Y-%m-%dT%H:%M', value.timetuple())
+        try:
+            return strftime('%Y-%m-%dT%H:%M', value.timetuple())
+        except ValueError:
+            return ''
 
     def display(self, value):
         if value is None: