diff --git a/forms/DateField.php b/forms/DateField.php
index 335deae33..63ff71f57 100755
--- a/forms/DateField.php
+++ b/forms/DateField.php
@@ -210,8 +210,11 @@ class DateField extends TextField {
 		if(Validator::get_javascript_validator_handler() == 'none') return true;
 
 		if($this->getConfig('dmyfields')) {
-			$error = _t('DateField.VALIDATIONJS', 'Please enter a valid date format (DD/MM/YYYY).');
-			$error = 'Please enter a valid date format (DD/MM/YYYY) from dmy.';
+			$error = _t('DateField.VALIDATIONJS', 'Please enter a valid date format.');
+			// Remove hardcoded date formats from translated strings
+			$error = preg_replace('/\(.*\)/', '', $error);
+			$error .= ' (' . $this->getConfig('dateformat') .')';
+			
 			$jsFunc =<<<JS
 Behaviour.register({
 	"#$formID": {
@@ -497,6 +500,8 @@ class DateField_View_JQuery {
 	 */
 	static $locale_map = array(
 		'en_GB' => 'en-GB',
+		'en_US' => 'en-US', 
+		'en_NZ' => 'en-GB', 
 		'fr_CH' => 'fr-CH',
 		'pt_BR' => 'pt-BR',
 		'sr_SR' => 'sr-SR',
diff --git a/lang/en_US.php b/lang/en_US.php
index 694e37ff4..72b427977 100644
--- a/lang/en_US.php
+++ b/lang/en_US.php
@@ -150,7 +150,7 @@ $lang['en_US']['Date']['YEAR'] = ' year';
 $lang['en_US']['Date']['YEARS'] = ' years';
 $lang['en_US']['DateField']['NOTSET'] = 'not set';
 $lang['en_US']['DateField']['TODAY'] = 'today';
-$lang['en_US']['DateField']['VALIDATIONJS'] = 'Please enter a valid date format (DD/MM/YYYY).';
+$lang['en_US']['DateField']['VALIDATIONJS'] = 'Please enter a valid date format.';
 $lang['en_US']['DateField']['VALIDDATEFORMAT2'] = 'Please enter a valid date format (%s).';
 $lang['en_US']['DateField']['VALIDDATEMAXDATE'] = 'Your date has to be older or matching the maximum allowed date (%s)';
 $lang['en_US']['DateField']['VALIDDATEMINDATE'] = 'Your date has to be newer or matching the minimum allowed date (%s)';
diff --git a/thirdparty/Zend/Locale/Data/en_US.xml b/thirdparty/Zend/Locale/Data/en_US.xml
index eef47372d..e6fc80ddf 100644
--- a/thirdparty/Zend/Locale/Data/en_US.xml
+++ b/thirdparty/Zend/Locale/Data/en_US.xml
@@ -7,4 +7,68 @@
 		<language type="en"/>
 		<territory type="US"/>
 	</identity>
+	<dates>
+		<calendars>
+			<calendar type="gregorian">
+				<dateFormats>
+					<dateFormatLength type="full">
+						<dateFormat>
+							<pattern>EEEE, d MMMM yyyy</pattern>
+						</dateFormat>
+					</dateFormatLength>
+					<dateFormatLength type="long">
+						<dateFormat>
+							<pattern>d MMMM yyyy</pattern>
+						</dateFormat>
+					</dateFormatLength>
+					<dateFormatLength type="medium">
+						<dateFormat>
+							<pattern>MM/dd/yyyy</pattern>
+						</dateFormat>
+					</dateFormatLength>
+					<dateFormatLength type="short">
+						<dateFormat>
+							<pattern>MM/dd/yyyy</pattern>
+						</dateFormat>
+					</dateFormatLength>
+				</dateFormats>
+				<timeFormats>
+					<timeFormatLength type="full">
+						<timeFormat>
+							<pattern>HH:mm:ss v</pattern>
+						</timeFormat>
+					</timeFormatLength>
+					<timeFormatLength type="long">
+						<timeFormat>
+							<pattern>HH:mm:ss z</pattern>
+						</timeFormat>
+					</timeFormatLength>
+					<timeFormatLength type="medium">
+						<timeFormat>
+							<pattern>hh:mm a</pattern>
+						</timeFormat>
+					</timeFormatLength>
+					<timeFormatLength type="short">
+						<timeFormat>
+							<pattern>hh:mm a</pattern>
+						</timeFormat>
+					</timeFormatLength>
+				</timeFormats>
+			</calendar>
+		</calendars>
+		<timeZoneNames>
+			<metazone type="America_Eastern">
+				<commonlyUsed>true</commonlyUsed>
+			</metazone>
+			<metazone type="America_Central">
+				<commonlyUsed>true</commonlyUsed>
+			</metazone>
+			<metazone type="America_Mountain">
+				<commonlyUsed>true</commonlyUsed>
+			</metazone>
+			<metazone type="America_Pacific">
+				<commonlyUsed>true</commonlyUsed>
+			</metazone>
+		</timeZoneNames>
+	</dates>
 </ldml>