diff --git a/hakyll.cabal b/hakyll.cabal
--- a/hakyll.cabal
+++ b/hakyll.cabal
@@ -1,5 +1,5 @@
 Name:    hakyll
-Version: 3.5.0.0
+Version: 3.5.1.0
 
 Synopsis: A static website compiler library
 Description:
diff --git a/src/Hakyll/Core/Run.hs b/src/Hakyll/Core/Run.hs
--- a/src/Hakyll/Core/Run.hs
+++ b/src/Hakyll/Core/Run.hs
@@ -14,6 +14,7 @@
 import Data.Map (Map)
 import Data.Monoid (mempty, mappend)
 import Prelude hiding (reverse)
+import System.Exit (ExitCode (..), exitWith)
 import System.FilePath ((</>))
 import qualified Data.Map as M
 import qualified Data.Set as S
@@ -74,16 +75,16 @@
         }
 
     case result of
-        Left e             ->
+        Left e             -> do
             thrown logger e
-        Right ((), state') ->
+            flushLogger logger
+            exitWith $ ExitFailure 1
+        Right ((), state') -> do
             -- We want to save the final dependency graph for the next run
             Store.set store ["Hakyll.Core.Run.run", "dependencies"] $
                 analyzerGraph $ hakyllAnalyzer state'
-
-    -- Flush and return
-    flushLogger logger
-    return ruleSet
+            flushLogger logger
+            return ruleSet
 
 data RuntimeEnvironment = RuntimeEnvironment
     { hakyllLogger           :: Logger
diff --git a/src/Hakyll/Web/Page/Metadata.hs b/src/Hakyll/Web/Page/Metadata.hs
--- a/src/Hakyll/Web/Page/Metadata.hs
+++ b/src/Hakyll/Web/Page/Metadata.hs
@@ -186,6 +186,7 @@
         [ "%a, %d %b %Y %H:%M:%S UT"
         , "%Y-%m-%dT%H:%M:%SZ"
         , "%Y-%m-%d %H:%M:%S"
+        , "%Y-%m-%d"
         , "%B %e, %Y %l:%M %p"
         , "%B %e, %Y"
         ]