diff --git a/code/compat/pages/BlogEntry.php b/code/compat/pages/BlogEntry.php
index 190d475..3111a39 100644
--- a/code/compat/pages/BlogEntry.php
+++ b/code/compat/pages/BlogEntry.php
@@ -27,7 +27,7 @@ class BlogEntry extends BlogPost implements MigratableObject
     /**
      * {@inheritdoc}
      */
-    public function canCreate($member = null)
+    public function canCreate($member = null, $context = array())
     {
         return false;
     }
diff --git a/code/compat/pages/BlogHolder.php b/code/compat/pages/BlogHolder.php
index 49bc287..653a856 100644
--- a/code/compat/pages/BlogHolder.php
+++ b/code/compat/pages/BlogHolder.php
@@ -28,7 +28,7 @@ class BlogHolder extends BlogTree implements MigratableObject
     /**
      * {@inheritdoc}
      */
-    public function canCreate($member = null)
+    public function canCreate($member = null, $context = array())
     {
         return false;
     }
@@ -64,7 +64,7 @@ class BlogHolder extends BlogTree implements MigratableObject
         } else {
             $message = "DRAFT: ";
         }
-        
+
         return $message . $this->Title;
     }
 }
diff --git a/code/compat/pages/BlogTree.php b/code/compat/pages/BlogTree.php
index 0998de2..9fa2617 100644
--- a/code/compat/pages/BlogTree.php
+++ b/code/compat/pages/BlogTree.php
@@ -21,7 +21,7 @@ class BlogTree extends Page implements MigratableObject
     /**
      * {@inheritdoc}
      */
-    public function canCreate($member = null)
+    public function canCreate($member = null, $context = array())
     {
         return false;
     }
@@ -43,7 +43,7 @@ class BlogTree extends Page implements MigratableObject
         } else {
             $message = "DRAFT: ";
         }
-        
+
         return $message . $this->Title;
     }
 }
diff --git a/code/extensions/BlogFilter.php b/code/extensions/BlogFilter.php
index 65dc027..29dcd6c 100644
--- a/code/extensions/BlogFilter.php
+++ b/code/extensions/BlogFilter.php
@@ -17,7 +17,7 @@ class BlogFilter extends Lumberjack
         $staged = parent::stageChildren($showAll);
 
         if (!$this->shouldFilter() && $this->subclassForBlog() && !Permission::check('VIEW_DRAFT_CONTENT')) {
-            $stage = Versioned::current_stage();
+            $stage = Versioned::get_stage();
 
             if ($stage == 'Stage') {
                 $stage = '';
diff --git a/code/extensions/BlogPostFilter.php b/code/extensions/BlogPostFilter.php
index 1795bc8..26949eb 100644
--- a/code/extensions/BlogPostFilter.php
+++ b/code/extensions/BlogPostFilter.php
@@ -14,16 +14,19 @@ class BlogPostFilter extends DataExtension
      *
      * @param SQLQuery $query
      */
-    public function augmentSQL(SQLQuery &$query)
+    public function augmentSQL(SQLSelect $query, DataQuery $dataQuery = null)
     {
-        $stage = Versioned::current_stage();
+        $stage = Versioned::get_stage();
 
         if (Controller::curr() instanceof LeftAndMain) {
             return;
         }
 
         if ($stage == 'Live' || !Permission::check('VIEW_DRAFT_CONTENT')) {
-            $query->addWhere(sprintf('"PublishDate" < \'%s\'', Convert::raw2sql(SS_Datetime::now())));
+            $query->addWhere(sprintf(
+                '"PublishDate" < \'%s\'',
+                Convert::raw2sql(SS_Datetime::now())
+            ));
         }
     }
 
@@ -38,8 +41,11 @@ class BlogPostFilter extends DataExtension
      * @param mixed $dataQuery
      * @param mixed $parent
      */
-    public function augmentLoadLazyFields(SQLQuery &$query, &$dataQuery, $parent)
-    {
+    public function augmentLoadLazyFields(
+        SQLSelect &$query,
+        DataQuery &$dataQuery = null,
+        $dataObject
+    ) {
         $dataQuery->innerJoin('BlogPost', '"SiteTree"."ID" = "BlogPost"."ID"');
     }
 }
diff --git a/code/model/Blog.php b/code/model/Blog.php
index 0ce1b08..1d4ff6c 100644
--- a/code/model/Blog.php
+++ b/code/model/Blog.php
@@ -1,5 +1,7 @@
 <?php
 
+use SilverStripe\Model\FieldType\DBDatetime;
+
 /**
  * Blog Holder
  *
@@ -1083,7 +1085,9 @@ class Blog_Controller extends Page_Controller
                 $date = sprintf('%s-01-01', $year);
             }
 
-            return DBField::create_field('Date', $date);
+            $obj = new DBDatetime('date');
+            $obj->setValue($date);
+            return $obj;
         }
 
         return null;
diff --git a/code/model/BlogCategory.php b/code/model/BlogCategory.php
index a678e40..b9186ac 100644
--- a/code/model/BlogCategory.php
+++ b/code/model/BlogCategory.php
@@ -80,7 +80,7 @@ class BlogCategory extends DataObject implements CategorisationObject
     /**
      * {@inheritdoc}
      */
-    protected function validate()
+    public function validate()
     {
         $validation = parent::validate();
         if($validation->valid()) {
@@ -131,13 +131,9 @@ class BlogCategory extends DataObject implements CategorisationObject
     }
 
     /**
-     * Inherits from the parent blog or can be overwritten using a DataExtension.
-     *
-     * @param null|Member $member
-     *
-     * @return bool
+     * {@inheritdoc}
      */
-    public function canCreate($member = null)
+    public function canCreate($member = null, $context = array())
     {
         $extended = $this->extendedCan(__FUNCTION__, $member);
 
diff --git a/code/model/BlogPost.php b/code/model/BlogPost.php
index 7e6ac15..9c46862 100644
--- a/code/model/BlogPost.php
+++ b/code/model/BlogPost.php
@@ -218,7 +218,7 @@ class BlogPost extends Page
                 'Authors',
                 _t('BlogPost.Authors', 'Authors'),
                 $self->getCandidateAuthors()->map()->toArray()
-            )->setMultiple(true);
+            );
 
             $authorNames = TextField::create(
                 'AuthorNames',
diff --git a/code/model/BlogTag.php b/code/model/BlogTag.php
index 47c9e57..caf744e 100644
--- a/code/model/BlogTag.php
+++ b/code/model/BlogTag.php
@@ -81,7 +81,7 @@ class BlogTag extends DataObject implements CategorisationObject
     /**
      * {@inheritdoc}
      */
-    protected function validate()
+    public function validate()
     {
         $validation = parent::validate();
         if($validation->valid()) {
@@ -132,13 +132,9 @@ class BlogTag extends DataObject implements CategorisationObject
     }
 
     /**
-     * Inherits from the parent blog or can be overwritten using a DataExtension.
-     *
-     * @param null|Member $member
-     *
-     * @return bool
+     * {@inheritdoc}
      */
-    public function canCreate($member = null)
+    public function canCreate($member = null, $context = array())
     {
         $extended = $this->extendedCan(__FUNCTION__, $member);
 
diff --git a/tests/blog.yml b/tests/blog.yml
index e664f88..cad0fc0 100755
--- a/tests/blog.yml
+++ b/tests/blog.yml
@@ -166,7 +166,7 @@ BlogPost:
     Authors: =>Member.BlogEditor,=>Member.Writer,=>Member.Contributor
   NullPublishDate:
     Title: 'No publish date'
-    PublishDate: 'NULL'
+    PublishDate: ''
     Parent: =>Blog.FourthBlog
     Authors: =>Member.BlogEditor,=>Member.Writer,=>Member.Contributor