diff --git a/src/IDF/Form/Field/Date.php b/src/IDF/Form/Field/Date.php
deleted file mode 100644
index 9ddb6c2..0000000
--- a/src/IDF/Form/Field/Date.php
+++ /dev/null
@@ -1,36 +0,0 @@
-<?php
-/* -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
-/*
-# ***** BEGIN LICENSE BLOCK *****
-# This file is part of InDefero, an open source project management application.
-# Copyright (C) 2008-2011 Céondo Ltd and contributors.
-#
-# InDefero is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 2 of the License, or
-# (at your option) any later version.
-#
-# InDefero is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program; if not, write to the Free Software
-# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
-#
-# ***** END LICENSE BLOCK ***** */
-
-class IDF_Form_Field_Date extends Pluf_Form_Field_Date
-{
-    public function clean($value) {
-        try {
-            return parent::clean($value);
-        } catch (Pluf_Form_Invalid $e) {
-            if(false === $this->required and empty($value)) {
-                return null;
-            }
-            throw $e;
-        }
-    }
-}
diff --git a/src/IDF/Form/Field/Datetime.php b/src/IDF/Form/Field/Datetime.php
deleted file mode 100644
index 04c4e29..0000000
--- a/src/IDF/Form/Field/Datetime.php
+++ /dev/null
@@ -1,36 +0,0 @@
-<?php
-/* -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
-/*
-# ***** BEGIN LICENSE BLOCK *****
-# This file is part of InDefero, an open source project management application.
-# Copyright (C) 2008-2011 Céondo Ltd and contributors.
-#
-# InDefero is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 2 of the License, or
-# (at your option) any later version.
-#
-# InDefero is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program; if not, write to the Free Software
-# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
-#
-# ***** END LICENSE BLOCK ***** */
-
-class IDF_Form_Field_Datetime extends Pluf_Form_Field_Datetime
-{
-    public function clean($value) {
-        try {
-            return parent::clean($value);
-        } catch (Pluf_Form_Invalid $e) {
-            if(false === $this->required and empty($value)) {
-                return null;
-            }
-            throw $e;
-        }
-    }
-}
diff --git a/src/IDF/Form/IssueCreate.php b/src/IDF/Form/IssueCreate.php
index 8c2ab16..d8f3244 100644
--- a/src/IDF/Form/IssueCreate.php
+++ b/src/IDF/Form/IssueCreate.php
@@ -112,7 +112,7 @@ class IDF_Form_IssueCreate extends Pluf_Form
                                                        'size' => 15,
                                                                     ),
                                             ));
-            $this->fields['due_dtime'] = new IDF_Form_Field_Date(
+            $this->fields['due_dtime'] = new Pluf_Form_Field_Date(
                                           array('required' => false,
                                                 'label' => __('Due date'),
                                                 'initial' => '',
diff --git a/src/IDF/Form/IssueUpdate.php b/src/IDF/Form/IssueUpdate.php
index 160f306..9421e11 100644
--- a/src/IDF/Form/IssueUpdate.php
+++ b/src/IDF/Form/IssueUpdate.php
@@ -103,7 +103,7 @@ class IDF_Form_IssueUpdate  extends IDF_Form_IssueCreate
                                                        'size' => 15,
                                                                     ),
                                             ));
-            $this->fields['due_dtime'] = new IDF_Form_Field_Date(
+            $this->fields['due_dtime'] = new Pluf_Form_Field_Date(
                                 array('required' => false,
                                     'label' => __('Due date'),
                                     'initial' => $this->issue->due_dtime,