Sort by taxonomy

sortbytaxonomy.php

$timestamps = get_terms( 'timestamp', array(
	'hide_empty' => true,
	'orderby' => 'name', 
) );
if ( ! empty( $timestamps ) && ! is_wp_error( $timestamps ) ){
	echo '<ul>';
	foreach ( $timestamps as $timestamp ) {
	    echo '<li>' . $timestamp->name . '</li>';
	    $args = array('post_type' => 'event',
	        'tax_query' => array(
	            array(
	            'taxonomy' => 'timestamp',
	            'field' => 'name',
	            'terms' => $timestamp->name,
	            ),
	        ),
	    );
	    $myposts = get_posts( $args );
	    foreach ( $myposts as $post ) : setup_postdata( $post ); ?>
	        <li>
	            <a href="<?php the_permalink(); ?>"><?php the_title(); ?></a>
	        </li>
	    <?php endforeach; 
	    wp_reset_postdata();
	}
	echo '</ul>';
}