Index: src/wp-admin/js/comment.js
===================================================================
--- src/wp-admin/js/comment.js	(revision 33347)
+++ src/wp-admin/js/comment.js	(working copy)
@@ -37,14 +37,18 @@
 
 		$('#timestampdiv').slideUp('normal');
 		$('.edit-timestamp').show();
-		$('#timestamp').html(
+
+		$( '#timestamp' ).html(
 			commentL10n.submittedOn + ' <b>' +
-			$( '#mm option[value="' + mm + '"]' ).text() + ' ' +
-			jj + ', ' +
-			aa + ' @ ' +
-			hh + ':' +
-			mn + '</b> '
+			commentL10n.dateFormat
+				.replace( '%1$s', $( 'option[value="' + mm + '"]', '#mm' ).attr( 'data-text' ) )
+				.replace( '%2$s', parseInt( jj, 10 ) )
+				.replace( '%3$s', aa )
+				.replace( '%4$s', ( '00' + hh ).slice( -2 ) )
+				.replace( '%5$s', ( '00' + mn ).slice( -2 ) ) +
+			'</b> '
 		);
+
 		return false;
 	});
 });
Index: src/wp-includes/script-loader.php
===================================================================
--- src/wp-includes/script-loader.php	(revision 33347)
+++ src/wp-includes/script-loader.php	(working copy)
@@ -523,7 +523,9 @@
 		$scripts->add( 'comment', "/wp-admin/js/comment$suffix.js", array( 'jquery', 'postbox' ) );
 		$scripts->add_data( 'comment', 'group', 1 );
 		did_action( 'init' ) && $scripts->localize( 'comment', 'commentL10n', array(
-			'submittedOn' => __('Submitted on:')
+			'submittedOn' => __( 'Submitted on:' ),
+			/* translators: 1: month, 2: day, 3: year, 4: hour, 5: minute */
+			'dateFormat' => __( '%1$s %2$s, %3$s @ %4$s:%5$s' )
 		) );
 
 		$scripts->add( 'admin-gallery', "/wp-admin/js/gallery$suffix.js", array( 'jquery-ui-sortable' ) );