The implementation of MySQL automatically increasing partitions every day

ALTER TABLE tb_3a_huandan_detail PARTITION BY RANGE (TO_DAYS(ServiceStartTime))
(
    PARTITION p20160523 VALUES LESS THAN (TO_DAYS('2016-05-23')),
    PARTITION p20160524 VALUES LESS THAN (TO_DAYS('2016-05-24')),
    PARTITION p20160525 VALUES LESS THAN (TO_DAYS('2016-05-25')),
    PARTITION p20160526 VALUES LESS THAN (TO_DAYS('2016-05-26')),
    PARTITION p20160527 VALUES LESS THAN (TO_DAYS('2016-05-27'))
)

DELIMITER $$

USE `nres`$$

DROP PROCEDURE IF EXISTS `create_Partition_3Ahuadan`$$

CREATE DEFINER=`nres`@`%` PROCEDURE `create_Partition_3Ahuadan`()
BEGIN
/* Transaction rollback, in fact, it has no effect here. ALTER TABLE is implicitly submitted and cannot be rolled back.  */
    DECLARE EXIT HANDLER FOR SQLEXCEPTION ROLLBACK;
    START TRANSACTION;

/* Check the maximum partition of this table in the system table and get the date of the largest partition.  When creating a partition, the name is stored in date format, which is convenient for later maintenance */
    SELECT REPLACE(partition_name,'p','') INTO @P12_Name FROM INFORMATION_SCHEMA.PARTITIONS
    WHERE table_name='tb_3a_huandan_detail' ORDER BY partition_ordinal_position DESC LIMIT 1;
     SET @Max_date= DATE(DATE_ADD(@P12_Name+0, INTERVAL 1 DAY))+0;
/* Modify the table, add one partition behind the largest partition, and add 1 day to the time range */
    SET @s1=CONCAT('ALTER TABLE tb_3a_huandan_detail ADD PARTITION (PARTITION p',@Max_date,' VALUES LESS THAN (TO_DAYS (''',DATE(@Max_date),''')))');
    /* Output view add partition statement*/
    SELECT @s1;
    PREPARE stmt2 FROM @s1;
    EXECUTE stmt2;
    DEALLOCATE PREPARE stmt2;
/* Take out the name of the smallest partition and delete it.
 Note: Deleting a partition will delete data in the partition at the same time, be careful */
    /*select partition_name into @P0_Name from INFORMATION_SCHEMA.PARTITIONS
    where table_name='tb_3a_huandan_detail' order by partition_ordinal_position limit 1;
    SET @s=concat('ALTER TABLE tb_3a_huandan_detail DROP PARTITION ',@P0_Name);
    PREPARE stmt1 FROM @s;
    EXECUTE stmt1;
    DEALLOCATE PREPARE stmt1; */
/* submit */
    COMMIT ;
 END$$

DELIMITER ;

DELIMITER ||
CREATE EVENT Partition_3Ahuadan_event
          ON SCHEDULE
          EVERY 1 day STARTS '2016-05-27 23:59:59'
          DO
      BEGIN

          CALL nres.`create_Partition_3Ahuadan`;

 END ||
DELIMITER ;