public function filter_by_multiday( $multiday = true ) {
		global $wpdb;

		$this->filter_query->join( "LEFT JOIN {$wpdb->postmeta} multiday_start_date
			ON ( {$wpdb->posts}.ID = multiday_start_date.post_id
			AND multiday_start_date.meta_key = '_EventStartDate' )" );
		$this->filter_query->join( "LEFT JOIN {$wpdb->postmeta} multiday_end_date
			ON ( {$wpdb->posts}.ID = multiday_end_date.post_id
			AND multiday_end_date.meta_key = '_EventEndDate' )" );

		// We're interested in the time only.
		$end_of_day_cutoff = tribe_end_of_day( 'today', 'H:i:s' );

		if ( '23:59:59' === $end_of_day_cutoff ) {
			/*
			 * An event is considered multi-day when the end date is not the same as the start date when
			 * using the "natural" end-of-day cutoff.
			 */
			$compare = $multiday ? '!=' : '=';
			$this->filter_query->where(
				"DATE( multiday_end_date.meta_value ) {$compare} DATE( multiday_start_date.meta_value )"
			);
		} else {
			/*
			 * An event is considered multi-day when the end date is after the end-of-day cutoff of the start date.
			 * Since the cut-off moves forward from midnight add 1 day to the start date.
			 */
			$compare = $multiday ? '>' : '<=';
			$this->filter_query->where(
				"multiday_end_date.meta_value {$compare} DATE_FORMAT( DATE_ADD( multiday_start_date.meta_value, INTERVAL 1 DAY ) , '%Y-%m-%d {$end_of_day_cutoff}' )"
			);
		}
	}