training_dates.php

	//START TRAINING DATES FILTER

	$start_date = new DateTime($_POST['date_start']);
	$start_date = $start_date->format('Ymd'); // Change the date format to what ACF expects
	$end_date = new DateTime($_POST['date_end']);
	$end_date = $end_date->format('Ymd'); // Change the date format to what ACF expects

	if(isset($_POST['date_start']) && $_POST['date_start'] &&
	isset($_POST['date_end']) && $_POST['date_end']) {

		$args['meta_query'][] = array(
			'key' => 'volunteer_probity_check_and_training_stage_%volunteer_training_date',
			'value' => array($start_date, $end_date),
			'type' => 'date',
			'compare' => 'BETWEEN'
		);
	}