* @param string $format Desired return format of the date.
	 * @return string
	 */
	public function get_start_date( $format = 'Y-m-d H:i:s' ) {
		/**
		 * Get the first recorded transaction.
		 * Refunds are okay b/c that would have initially given the user access.
		 */
		$txns = $this->get_transactions(
			array(
				'order'         => 'ASC',
				'orderby'       => 'date',
				'per_page'      => 1,
				'status'        => array( 'llms-txn-succeeded', 'llms-txn-refunded' ),
				'type'          => 'any',
				'no_found_rows' => true,
			)
		);
		if ( $txns['count'] ) {
			$txn  = array_pop( $txns['transactions'] );