public function get_data_attrs() {

		$attrs = array(
			'date_format' => 'data-format',
			'date_max'    => 'data-max-date',
			'date_min'    => 'data-min-date',
		);

		$data_attrs = '';
		foreach ( $attrs as $key => $attr ) {
			$val = ! empty( $this->field[ $key ] ) ? $this->field[ $key ] : null;
			if ( $val ) {
				$data_attrs .= sprintf( '%1$s="%2$s"', $attr, $val );
			}
		}
		return $data_attrs;

	}