Here is the code, I am using

<?php

$today = get_the_date('F j');

$args = array(
'post_type' => 'on-this-day',
'posts_per_page' => 1,
'post_parent'    => 0,
'post_status' => 'publish',
'date_query' => array(
 array(
   'before' => $today,
   'inclusive' => true,
 ),
),
);
$previous_post_query = new WP_Query( $args );

if ( $previous_post_query->have_posts() ):
while ( $previous_post_query->have_posts() ): $previous_post_query->the_post();
 $previous_post_link = get_permalink();
 $previous_post_title="What Happend On ". get_the_title() . '?' ;
 echo '<a class="prev" href="' . $previous_post_link . '">' . $previous_post_title . '</a>';
endwhile;
wp_reset_postdata();
else:
echo 'No previous post found.';
endif;

?>

The Output is always What Happend On July 1?