Index: wp-includes/default-widgets.php
===================================================================
--- wp-includes/default-widgets.php	(revision 21103)
+++ wp-includes/default-widgets.php	(working copy)
@@ -561,6 +561,7 @@
 		$title = apply_filters('widget_title', empty($instance['title']) ? __('Recent Posts') : $instance['title'], $instance, $this->id_base);
 		if ( empty( $instance['number'] ) || ! $number = absint( $instance['number'] ) )
  			$number = 10;
+		$show_date = isset( $instance['show_date'] ) ? $instance['show_date'] : false;
 
 		$r = new WP_Query( apply_filters( 'widget_posts_args', array( 'posts_per_page' => $number, 'no_found_rows' => true, 'post_status' => 'publish', 'ignore_sticky_posts' => true ) ) );
 		if ($r->have_posts()) :
@@ -569,7 +570,12 @@
 		<?php if ( $title ) echo $before_title . $title . $after_title; ?>
 		<ul>
 		<?php  while ($r->have_posts()) : $r->the_post(); ?>
-		<li><a href="<?php the_permalink() ?>" title="<?php echo esc_attr(get_the_title() ? get_the_title() : get_the_ID()); ?>"><?php if ( get_the_title() ) the_title(); else the_ID(); ?></a></li>
+			<li>
+				<a href="<?php the_permalink() ?>" title="<?php echo esc_attr(get_the_title() ? get_the_title() : get_the_ID()); ?>"><?php if ( get_the_title() ) the_title(); else the_ID(); ?></a>
+			<?php if ( $show_date ) : ?>
+				<?php echo '<span class="post-date">' . get_the_date() . '</span>'; ?>
+			<?php endif; ?>
+			</li>
 		<?php endwhile; ?>
 		</ul>
 		<?php echo $after_widget; ?>
@@ -587,6 +593,7 @@
 		$instance = $old_instance;
 		$instance['title'] = strip_tags($new_instance['title']);
 		$instance['number'] = (int) $new_instance['number'];
+		$instance['show_date'] = (bool) $new_instance['show_date'];
 		$this->flush_widget_cache();
 
 		$alloptions = wp_cache_get( 'alloptions', 'options' );
@@ -601,14 +608,18 @@
 	}
 
 	function form( $instance ) {
-		$title = isset($instance['title']) ? esc_attr($instance['title']) : '';
-		$number = isset($instance['number']) ? absint($instance['number']) : 5;
+		$title     = isset( $instance['title'] ) ? esc_attr( $instance['title'] ) : '';
+		$number    = isset( $instance['number'] ) ? absint( $instance['number'] ) : 5;
+		$show_date = isset( $instance['show_date'] ) ? (bool) $instance['show_date'] : false;
 ?>
-		<p><label for="<?php echo $this->get_field_id('title'); ?>"><?php _e('Title:'); ?></label>
-		<input class="widefat" id="<?php echo $this->get_field_id('title'); ?>" name="<?php echo $this->get_field_name('title'); ?>" type="text" value="<?php echo $title; ?>" /></p>
+		<p><label for="<?php echo $this->get_field_id( 'title' ); ?>"><?php _e( 'Title:' ); ?></label>
+		<input class="widefat" id="<?php echo $this->get_field_id( 'title' ); ?>" name="<?php echo $this->get_field_name( 'title' ); ?>" type="text" value="<?php echo $title; ?>" /></p>
 
-		<p><label for="<?php echo $this->get_field_id('number'); ?>"><?php _e('Number of posts to show:'); ?></label>
-		<input id="<?php echo $this->get_field_id('number'); ?>" name="<?php echo $this->get_field_name('number'); ?>" type="text" value="<?php echo $number; ?>" size="3" /></p>
+		<p><label for="<?php echo $this->get_field_id( 'number' ); ?>"><?php _e( 'Number of posts to show:' ); ?></label>
+		<input id="<?php echo $this->get_field_id( 'number' ); ?>" name="<?php echo $this->get_field_name( 'number' ); ?>" type="text" value="<?php echo $number; ?>" size="3" /></p>
+
+		<p><input class="checkbox" type="checkbox" <?php checked( $show_date ); ?> id="<?php echo $this->get_field_id( 'show_date' ); ?>" name="<?php echo $this->get_field_name( 'show_date' ); ?>" />
+		<label for="<?php echo $this->get_field_id( 'show_date' ); ?>"><?php _e( 'Display post date?' ); ?></p>
 <?php
 	}
 }