Grouping the results of a WordPress loop by month and year

example.php

<?php
$args = array(...);
$my_posts = new WP_Query( $args );
$the_year = '';
$the_month = '';
if ( $my_posts->have_posts() ) :
	while ( $my_posts->have_posts() ) :
		$my_posts->the_post();
		// Get the year of the post in YYYY format
		$post_year = get_the_time( 'Y' );
		if ( $post_year != $the_year ) {
			$the_year = $post_year;
			$the_month = '';
			echo '<h1>' . $the_year . '</h1>';
		}

		// Get the month of the post i.e. January, February etc.
		$post_month = get_thetime( 'F' );
		if ( $post_month != $the_month ) {
			$the_month = $post_month;
			echo '<h2>' . $post_month . '</h2>';
		}

		echo '<p><a href="' . get_permalink() . '">' . the_title() . '</a></p>';

	endwhile;
endif;