diff --git a/lib/interval.py b/lib/interval.py
index 4b7eea1..4ed5ebd 100644
--- a/lib/interval.py
+++ b/lib/interval.py
@@ -44,8 +44,8 @@ def decompose_interval(attrname):
             try:
                 value = int(value)
                 assert value >= 0
-            except (ValueError, AssertionError):
-                raise ValueError("Incorrect time interval")
+            except (ValueError, AssertionError) as e:
+                raise ValueError("Incorrect time interval", e)
             setattr(self, attrname, value * getattr(self, scl_name))
 
 
diff --git a/model.py b/model.py
index 3947a91..195122c 100644
--- a/model.py
+++ b/model.py
@@ -34,7 +34,6 @@ class RemoteIDMixin(object):
         self.id = "twitter:{}".format(id)
 
 
-
 @decompose_interval('policy_delete_every')
 @decompose_interval('policy_keep_younger')
 class Account(TimestampMixin, RemoteIDMixin):
@@ -67,6 +66,13 @@ class Account(TimestampMixin, RemoteIDMixin):
             value = timedelta(minutes=1)
         return value
 
+    @db.validates('policy_keep_latest')
+    def validate_empty_string_is_zero(self, key, value):
+        if type(value) == str and value.strip() == '':
+            return 0
+        return value
+
+
     # backref: tokens
     # backref: twitter_archives
     # backref: posts
diff --git a/routes.py b/routes.py
index e43f5f6..b4b8d2f 100644
--- a/routes.py
+++ b/routes.py
@@ -32,7 +32,9 @@ def touch_viewer(resp):
 def index():
     if g.viewer:
         return render_template('logged_in.html', scales=lib.interval_scales,
-                tweet_archive_failed = 'tweet_archive_failed' in request.args)
+                tweet_archive_failed = 'tweet_archive_failed' in request.args,
+                settings_error = 'settings_error' in request.args
+                )
     else:
         return render_template('index.html')
 
@@ -90,8 +92,11 @@ def settings():
             'policy_keep_younger_significand',
             'policy_keep_younger_scale',
             ):
-        if attr in request.form:
-            setattr(g.viewer.account, attr, request.form[attr])
+        try:
+            if attr in request.form:
+                setattr(g.viewer.account, attr, request.form[attr])
+        except ValueError:
+            return redirect(url_for('index', settings_error=''))
 
     db.session.commit()
 
diff --git a/templates/logged_in.html b/templates/logged_in.html
index 7b6ce95..3ae3879 100644
--- a/templates/logged_in.html
+++ b/templates/logged_in.html
@@ -37,6 +37,10 @@
 <div class='banner success'>Settings saved successfully</div>
 {% endif %}
 
+{% if settings_error %}
+<div class='banner error'>Something went wrong trying to save your settings. Please try again later.</div>
+{% endif %}
+
 <form action='{{url_for("settings")}}' method='post' enctype='multipart/form-data'>
 <p>Posts that are less than
     {{interval_input(g.viewer.account, 'policy_keep_younger', scales)}}