FacetWP index ACF date in F j, Y format

<?php

/**
 * Re-index after adding this filter to your functions.php
 * Replace 'my_date_facet' with the name of your facet
 * For other date formats, see: https://www.php.net/manual/en/function.date.php
 */
add_filter( 'facetwp_index_row', function( $params, $class ) {
	if ( 'my_date_facet' == $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 );