You’re not using the proper table name in your CONSTRAINT clause:
CONSTRAINT `booking_timeslots_ibfk_1` FOREIGN KEY (`bid`) REFERENCES `booking_dates` (`id`)
That should be:
CONSTRAINT `booking_timeslots_ibfk_1` FOREIGN KEY (`bid`) REFERENCES `$date_table_name` (`id`)
where $date_table_name (as I could see) is the correct table name.