functions.php

<?php

/**
 * Header for Date Archives
 *
 * @author Bill Erickson
 * @link http://www.billerickson.net/code/header-date-archives/
 */
function be_date_archive_header() {
	if( ! is_date() )
		return;
		
	if( is_year() )
		$title = get_query_var( 'year' );
	if( is_month() )
		$title = single_month_title( ' ', false );
	if( is_day() ) {
		$date = get_query_var( 'day' ) . single_month_title( ' ', false );
		$title = date( 'F j, Y', strtotime( $date ) );
	}
	
	if( $title )
		echo '<h1 class="archive-title">' . $title . '</h1>';
}
add_action( 'genesis_before_loop', 'be_date_archive_header' );