FacetWP index ACF date in F j, Y format

<?php

/**
 * reindex after adding or updating this filter
 */
add_filter( 'facetwp_index_row', function( $params, $class ) {
	if ( 'dates' == $params['facet_name'] ) {
		$raw_value = $params['facet_value'];
		$params['facet_display_value'] = date( 'F j, Y', strtotime( $raw_value ) ); // "April 10, 2019" for the display value
	}
	return $params;
}, 10, 2 );